RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Thanks for your idea, Marek and Hans. This change makes sense. And I've already
verified it. I'll resubmit my change soon.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 24, 2014 8:43 PM
To: Marek Szyprowski; Fang Chen-B47543; m.che...@samsung.com;
v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/24/2014 02:40 PM, Marek Szyprowski wrote:
> Hello,
>
> On 2014-09-10 09:00, Hans Verkuil wrote:
>> On 09/10/14 07:28, Fancy Fang wrote:
>>> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
>>> will assign the corresponding offset to the 'boff' field of the
>>> videobuf_buffer for each requested buffer sequentially. Later, user
>>> may call mmap() to map one or all of the buffers with the 'offset'
>>> parameter which is equal to its 'boff' value. Obviously, the 'offset'
>>> value is only used to find the matched buffer instead of to be the
>>> real offset from the buffer's physical start address as used by
>>> vm_iomap_memory(). So, in some case that if the offset is not zero,
>>> vm_iomap_memory() will fail.
>> Is this just a fix for something that can fail theoretically, or do
>> you actually have a case where this happens? I am very reluctant to
>> make any changes to videobuf. Drivers should all migrate to vb2.
>>
>> I have CC-ed Marek as well since he knows a lot more about this stuff
>> than I do.
>
> I'm sorry for a delay, I was really busy with other things.
>
>>> Signed-off-by: Fancy Fang
>>> ---
>>> drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
>>> b/drivers/media/v4l2-core/videobuf-dma-contig.c
>>> index bf80f0f..8bd9889 100644
>>> --- a/drivers/media/v4l2-core/videobuf-dma-contig.c
>>> +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
>>> @@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
>>> *q,
>>> /* Try to remap memory */
>>> size = vma->vm_end - vma->vm_start;
>>> vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
>>> -retval = vm_iomap_memory(vma, mem->dma_handle, size);
>>> +retval = remap_pfn_range(vma, vma->vm_start,
>>> + mem->dma_handle >> PAGE_SHIFT,
>>> + size, vma->vm_page_prot);
>>> if (retval) {
>>> dev_err(q->dev, "mmap: remap failed with error %d. ",
>>> retval);
>
> I think we don't need to revert the code to use remap_pfn_range()
> again (like it was in pre v3.10 times). The simplest way will be to
> correctly fix
> vma->vm_pgoff and set it to zero before calling vm_iomap_memory(). It
> vma->is
> done the same way in vb2_dma_contig.c:vb2_dc_mmap().
>
> To sum up - please change your patch: keep vm_iomap_memory() call and
> add "vma->vm_pgoff = 0;" line before it with suitable comment.
Much better, I agree completely.
Regards,
Hans
RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Thanks for your idea, Marek and Hans. This change makes sense. And I've already
verified it. I'll resubmit my change soon.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 24, 2014 8:43 PM
To: Marek Szyprowski; Fang Chen-B47543; m.che...@samsung.com;
v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/24/2014 02:40 PM, Marek Szyprowski wrote:
> Hello,
>
> On 2014-09-10 09:00, Hans Verkuil wrote:
>> On 09/10/14 07:28, Fancy Fang wrote:
>>> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
>>> will assign the corresponding offset to the 'boff' field of the
>>> videobuf_buffer for each requested buffer sequentially. Later, user
>>> may call mmap() to map one or all of the buffers with the 'offset'
>>> parameter which is equal to its 'boff' value. Obviously, the 'offset'
>>> value is only used to find the matched buffer instead of to be the
>>> real offset from the buffer's physical start address as used by
>>> vm_iomap_memory(). So, in some case that if the offset is not zero,
>>> vm_iomap_memory() will fail.
>> Is this just a fix for something that can fail theoretically, or do
>> you actually have a case where this happens? I am very reluctant to
>> make any changes to videobuf. Drivers should all migrate to vb2.
>>
>> I have CC-ed Marek as well since he knows a lot more about this stuff
>> than I do.
>
> I'm sorry for a delay, I was really busy with other things.
>
>>> Signed-off-by: Fancy Fang
>>> ---
>>> drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
>>> b/drivers/media/v4l2-core/videobuf-dma-contig.c
>>> index bf80f0f..8bd9889 100644
>>> --- a/drivers/media/v4l2-core/videobuf-dma-contig.c
>>> +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
>>> @@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
>>> *q,
>>> /* Try to remap memory */
>>> size = vma->vm_end - vma->vm_start;
>>> vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
>>> -retval = vm_iomap_memory(vma, mem->dma_handle, size);
>>> +retval = remap_pfn_range(vma, vma->vm_start,
>>> + mem->dma_handle >> PAGE_SHIFT,
>>> + size, vma->vm_page_prot);
>>> if (retval) {
>>> dev_err(q->dev, "mmap: remap failed with error %d. ",
>>> retval);
>
> I think we don't need to revert the code to use remap_pfn_range()
> again (like it was in pre v3.10 times). The simplest way will be to
> correctly fix
> vma->vm_pgoff and set it to zero before calling vm_iomap_memory(). It
> vma->is
> done the same way in vb2_dma_contig.c:vb2_dc_mmap().
>
> To sum up - please change your patch: keep vm_iomap_memory() call and
> add "vma->vm_pgoff = 0;" line before it with suitable comment.
Much better, I agree completely.
Regards,
Hans
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Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On 09/24/2014 02:40 PM, Marek Szyprowski wrote:
Hello,
On 2014-09-10 09:00, Hans Verkuil wrote:
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make
any changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff
than I do.
I'm sorry for a delay, I was really busy with other things.
Signed-off-by: Fancy Fang
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma->vm_end - vma->vm_start;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-retval = vm_iomap_memory(vma, mem->dma_handle, size);
+retval = remap_pfn_range(vma, vma->vm_start,
+ mem->dma_handle >> PAGE_SHIFT,
+ size, vma->vm_page_prot);
if (retval) {
dev_err(q->dev, "mmap: remap failed with error %d. ",
retval);
I think we don't need to revert the code to use remap_pfn_range() again (like
it was in pre v3.10 times). The simplest way will be to correctly fix
vma->vm_pgoff and set it to zero before calling vm_iomap_memory(). It is
done the same way in vb2_dma_contig.c:vb2_dc_mmap().
To sum up - please change your patch: keep vm_iomap_memory() call and add
"vma->vm_pgoff = 0;" line before it with suitable comment.
Much better, I agree completely.
Regards,
Hans
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Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Hello,
On 2014-09-10 09:00, Hans Verkuil wrote:
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make
any changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff
than I do.
I'm sorry for a delay, I was really busy with other things.
Signed-off-by: Fancy Fang
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma->vm_end - vma->vm_start;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- retval = vm_iomap_memory(vma, mem->dma_handle, size);
+ retval = remap_pfn_range(vma, vma->vm_start,
+mem->dma_handle >> PAGE_SHIFT,
+size, vma->vm_page_prot);
if (retval) {
dev_err(q->dev, "mmap: remap failed with error %d. ",
retval);
I think we don't need to revert the code to use remap_pfn_range() again
(like
it was in pre v3.10 times). The simplest way will be to correctly fix
vma->vm_pgoff and set it to zero before calling vm_iomap_memory(). It is
done the same way in vb2_dma_contig.c:vb2_dc_mmap().
To sum up - please change your patch: keep vm_iomap_memory() call and add
"vma->vm_pgoff = 0;" line before it with suitable comment.
Best regards
--
Marek Szyprowski, PhD
Samsung R Institute Poland
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On 09/24/2014 05:29 AM, chen.f...@freescale.com wrote: Thanks a lot, Hans. I know the reason that you use vm_iomap_memory() instead of remap_pfn_range(). But according to my analysis, the sanity check is not suitable for v4l2 buffers mapping. You can check the code logic to see this. The logic relating to vm_pgoff might not be suitable, but other checks are. OK, I've looked at this a bit more and what I don't understand is why this has never caused problems before. Would this perhaps just work on intel architecture? Most platform drivers that would typically use the arm architecture use vb2 by now, so that might explain it. Anyway, put back the relevant checks and I'll Ack it. Migration to vb2 is not a quick job and it is not on our schedule yet. You really should do this. At some point the old videobuf will go away. More important, vb2 has support for the dmabuf API allowing you to share buffers between v4l and drm/kms. There are many other advantages of moving to vb2 including proper instrumentation and a control flow that doesn't make you go insane like vb1 does. And if you are still using the old v4l2-int-device API, then that's already no longer available as an API and is only used by a staging driver that will be removed soon. This is going to cause you major headaches if you want to support recent and upcoming kernels. Regards, Hans I just need you to check the code logic and make a decision for this. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Tuesday, September 23, 2014 2:10 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). Hi Fancy Fang, I do have a few comments: 1) One reason why the switch to vm_iomap_memory() was made originally was that that function did a bunch of sanity checks. Since this patch moves back to remap_pfn_range() those sanity checks are lost and should be reinstated. 2) You need Marek's Ack as well since he understands the memory code much better than I do. 3) There are efforts underway to make a modern i.mx6 video driver based on vb2 and all the other modern V4L2 APIs, wouldn't it be much better if freescale jumps on board and starts working on that code as well? See e.g. this mail thread: http://www.spinics.net/lists/linux-media/msg79078.html I assume this refers to the same hardware. The official freescale driver for that hardware is horrendous. If you are writing code for unrelated hardware, then you should move over to vb2 yourself. videobuf should not be used anymore for new drivers. 4) I still do not entirely understand the control flow and I will have to take another look. I'll see if I can do that tomorrow. Regards, Hans On 09/23/2014 05:11 AM, chen.f...@freescale.com wrote: Hans, Do you have any more comment on this patch? Best regards, Fancy Fang -Original Message- From: Fang Chen-B47543 Sent: Wednesday, September 10, 2014 3:29 PM To: 'Hans Verkuil'; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On the Freescale imx6 platform which belongs to ARM architecture. The driver is our local v4l2 output driver which is not upstream yet unfortunately. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Wednesday, September 10, 2014 3:21 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On 09/10/14 09:14, chen.f...@freescale.com wrote: It is not a theoretically issue, it is a real case that the mapping failed issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel. So I need your confirmation on it. With which driver does this happen? On which architecture? Regards, Hans Thanks. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Wednesday, September 10, 2014 3:01 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On 09/10/14 07:28, Fancy Fang wrote: When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core will assign the corresponding offset to the 'boff' field of the videobuf_buffer for each requested buffer sequentially. Later, user may call mmap
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On 09/24/2014 05:29 AM, chen.f...@freescale.com wrote: Thanks a lot, Hans. I know the reason that you use vm_iomap_memory() instead of remap_pfn_range(). But according to my analysis, the sanity check is not suitable for v4l2 buffers mapping. You can check the code logic to see this. The logic relating to vm_pgoff might not be suitable, but other checks are. OK, I've looked at this a bit more and what I don't understand is why this has never caused problems before. Would this perhaps just work on intel architecture? Most platform drivers that would typically use the arm architecture use vb2 by now, so that might explain it. Anyway, put back the relevant checks and I'll Ack it. Migration to vb2 is not a quick job and it is not on our schedule yet. You really should do this. At some point the old videobuf will go away. More important, vb2 has support for the dmabuf API allowing you to share buffers between v4l and drm/kms. There are many other advantages of moving to vb2 including proper instrumentation and a control flow that doesn't make you go insane like vb1 does. And if you are still using the old v4l2-int-device API, then that's already no longer available as an API and is only used by a staging driver that will be removed soon. This is going to cause you major headaches if you want to support recent and upcoming kernels. Regards, Hans I just need you to check the code logic and make a decision for this. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Tuesday, September 23, 2014 2:10 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). Hi Fancy Fang, I do have a few comments: 1) One reason why the switch to vm_iomap_memory() was made originally was that that function did a bunch of sanity checks. Since this patch moves back to remap_pfn_range() those sanity checks are lost and should be reinstated. 2) You need Marek's Ack as well since he understands the memory code much better than I do. 3) There are efforts underway to make a modern i.mx6 video driver based on vb2 and all the other modern V4L2 APIs, wouldn't it be much better if freescale jumps on board and starts working on that code as well? See e.g. this mail thread: http://www.spinics.net/lists/linux-media/msg79078.html I assume this refers to the same hardware. The official freescale driver for that hardware is horrendous. If you are writing code for unrelated hardware, then you should move over to vb2 yourself. videobuf should not be used anymore for new drivers. 4) I still do not entirely understand the control flow and I will have to take another look. I'll see if I can do that tomorrow. Regards, Hans On 09/23/2014 05:11 AM, chen.f...@freescale.com wrote: Hans, Do you have any more comment on this patch? Best regards, Fancy Fang -Original Message- From: Fang Chen-B47543 Sent: Wednesday, September 10, 2014 3:29 PM To: 'Hans Verkuil'; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On the Freescale imx6 platform which belongs to ARM architecture. The driver is our local v4l2 output driver which is not upstream yet unfortunately. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Wednesday, September 10, 2014 3:21 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On 09/10/14 09:14, chen.f...@freescale.com wrote: It is not a theoretically issue, it is a real case that the mapping failed issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel. So I need your confirmation on it. With which driver does this happen? On which architecture? Regards, Hans Thanks. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Wednesday, September 10, 2014 3:01 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On 09/10/14 07:28, Fancy Fang wrote: When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core will assign the corresponding offset to the 'boff' field of the videobuf_buffer for each requested buffer sequentially. Later, user may call mmap
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Hello,
On 2014-09-10 09:00, Hans Verkuil wrote:
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make
any changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff
than I do.
I'm sorry for a delay, I was really busy with other things.
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
- retval = vm_iomap_memory(vma, mem-dma_handle, size);
+ retval = remap_pfn_range(vma, vma-vm_start,
+mem-dma_handle PAGE_SHIFT,
+size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
I think we don't need to revert the code to use remap_pfn_range() again
(like
it was in pre v3.10 times). The simplest way will be to correctly fix
vma-vm_pgoff and set it to zero before calling vm_iomap_memory(). It is
done the same way in vb2_dma_contig.c:vb2_dc_mmap().
To sum up - please change your patch: keep vm_iomap_memory() call and add
vma-vm_pgoff = 0; line before it with suitable comment.
Best regards
--
Marek Szyprowski, PhD
Samsung RD Institute Poland
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
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Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On 09/24/2014 02:40 PM, Marek Szyprowski wrote:
Hello,
On 2014-09-10 09:00, Hans Verkuil wrote:
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make
any changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff
than I do.
I'm sorry for a delay, I was really busy with other things.
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
-retval = vm_iomap_memory(vma, mem-dma_handle, size);
+retval = remap_pfn_range(vma, vma-vm_start,
+ mem-dma_handle PAGE_SHIFT,
+ size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
I think we don't need to revert the code to use remap_pfn_range() again (like
it was in pre v3.10 times). The simplest way will be to correctly fix
vma-vm_pgoff and set it to zero before calling vm_iomap_memory(). It is
done the same way in vb2_dma_contig.c:vb2_dc_mmap().
To sum up - please change your patch: keep vm_iomap_memory() call and add
vma-vm_pgoff = 0; line before it with suitable comment.
Much better, I agree completely.
Regards,
Hans
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RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Thanks for your idea, Marek and Hans. This change makes sense. And I've already
verified it. I'll resubmit my change soon.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 24, 2014 8:43 PM
To: Marek Szyprowski; Fang Chen-B47543; m.che...@samsung.com;
v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/24/2014 02:40 PM, Marek Szyprowski wrote:
Hello,
On 2014-09-10 09:00, Hans Verkuil wrote:
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do
you actually have a case where this happens? I am very reluctant to
make any changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff
than I do.
I'm sorry for a delay, I was really busy with other things.
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
*q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
-retval = vm_iomap_memory(vma, mem-dma_handle, size);
+retval = remap_pfn_range(vma, vma-vm_start,
+ mem-dma_handle PAGE_SHIFT,
+ size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
I think we don't need to revert the code to use remap_pfn_range()
again (like it was in pre v3.10 times). The simplest way will be to
correctly fix
vma-vm_pgoff and set it to zero before calling vm_iomap_memory(). It
vma-is
done the same way in vb2_dma_contig.c:vb2_dc_mmap().
To sum up - please change your patch: keep vm_iomap_memory() call and
add vma-vm_pgoff = 0; line before it with suitable comment.
Much better, I agree completely.
Regards,
Hans
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RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Thanks for your idea, Marek and Hans. This change makes sense. And I've already
verified it. I'll resubmit my change soon.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 24, 2014 8:43 PM
To: Marek Szyprowski; Fang Chen-B47543; m.che...@samsung.com;
v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/24/2014 02:40 PM, Marek Szyprowski wrote:
Hello,
On 2014-09-10 09:00, Hans Verkuil wrote:
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do
you actually have a case where this happens? I am very reluctant to
make any changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff
than I do.
I'm sorry for a delay, I was really busy with other things.
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
*q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
-retval = vm_iomap_memory(vma, mem-dma_handle, size);
+retval = remap_pfn_range(vma, vma-vm_start,
+ mem-dma_handle PAGE_SHIFT,
+ size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
I think we don't need to revert the code to use remap_pfn_range()
again (like it was in pre v3.10 times). The simplest way will be to
correctly fix
vma-vm_pgoff and set it to zero before calling vm_iomap_memory(). It
vma-is
done the same way in vb2_dma_contig.c:vb2_dc_mmap().
To sum up - please change your patch: keep vm_iomap_memory() call and
add vma-vm_pgoff = 0; line before it with suitable comment.
Much better, I agree completely.
Regards,
Hans
RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Thanks a lot, Hans. I know the reason that you use vm_iomap_memory() instead of remap_pfn_range(). But according to my analysis, the sanity check is not suitable for v4l2 buffers mapping. You can check the code logic to see this. Migration to vb2 is not a quick job and it is not on our schedule yet. I just need you to check the code logic and make a decision for this. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Tuesday, September 23, 2014 2:10 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). Hi Fancy Fang, I do have a few comments: 1) One reason why the switch to vm_iomap_memory() was made originally was that that function did a bunch of sanity checks. Since this patch moves back to remap_pfn_range() those sanity checks are lost and should be reinstated. 2) You need Marek's Ack as well since he understands the memory code much better than I do. 3) There are efforts underway to make a modern i.mx6 video driver based on vb2 and all the other modern V4L2 APIs, wouldn't it be much better if freescale jumps on board and starts working on that code as well? See e.g. this mail thread: http://www.spinics.net/lists/linux-media/msg79078.html I assume this refers to the same hardware. The official freescale driver for that hardware is horrendous. If you are writing code for unrelated hardware, then you should move over to vb2 yourself. videobuf should not be used anymore for new drivers. 4) I still do not entirely understand the control flow and I will have to take another look. I'll see if I can do that tomorrow. Regards, Hans On 09/23/2014 05:11 AM, chen.f...@freescale.com wrote: > Hans, > Do you have any more comment on this patch? > > Best regards, > Fancy Fang > > -Original Message- > From: Fang Chen-B47543 > Sent: Wednesday, September 10, 2014 3:29 PM > To: 'Hans Verkuil'; m.che...@samsung.com; v...@zeniv.linux.org.uk > Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; > linux-kernel@vger.kernel.org; Marek Szyprowski > Subject: RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() > with remap_pfn_range(). > > On the Freescale imx6 platform which belongs to ARM architecture. The driver > is our local v4l2 output driver which is not upstream yet unfortunately. > > Best regards, > Fancy Fang > > -Original Message- > From: Hans Verkuil [mailto:hverk...@xs4all.nl] > Sent: Wednesday, September 10, 2014 3:21 PM > To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk > Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; > linux-kernel@vger.kernel.org; Marek Szyprowski > Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() > with remap_pfn_range(). > > On 09/10/14 09:14, chen.f...@freescale.com wrote: >> It is not a theoretically issue, it is a real case that the mapping failed >> issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel. >> So I need your confirmation on it. > > With which driver does this happen? On which architecture? > > Regards, > > Hans > >> >> Thanks. >> >> Best regards, >> Fancy Fang >> >> -Original Message- >> From: Hans Verkuil [mailto:hverk...@xs4all.nl] >> Sent: Wednesday, September 10, 2014 3:01 PM >> To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk >> Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; >> linux-kernel@vger.kernel.org; Marek Szyprowski >> Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() >> with remap_pfn_range(). >> >> On 09/10/14 07:28, Fancy Fang wrote: >>> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core >>> will assign the corresponding offset to the 'boff' field of the >>> videobuf_buffer for each requested buffer sequentially. Later, user >>> may call mmap() to map one or all of the buffers with the 'offset' >>> parameter which is equal to its 'boff' value. Obviously, the 'offset' >>> value is only used to find the matched buffer instead of to be the >>> real offset from the buffer's physical start address as used by >>> vm_iomap_memory(). So, in some case that if the offset is not zero, >>> vm_iomap_memory() will fail. >> >> Is this just a fix for something that can fail theoretically, or do you >> actually have a case where this happens? I am very reluctant to make any >> changes to videobuf. Drivers should all migrate to vb2. >> >> I
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Hi Fancy Fang, I do have a few comments: 1) One reason why the switch to vm_iomap_memory() was made originally was that that function did a bunch of sanity checks. Since this patch moves back to remap_pfn_range() those sanity checks are lost and should be reinstated. 2) You need Marek's Ack as well since he understands the memory code much better than I do. 3) There are efforts underway to make a modern i.mx6 video driver based on vb2 and all the other modern V4L2 APIs, wouldn't it be much better if freescale jumps on board and starts working on that code as well? See e.g. this mail thread: http://www.spinics.net/lists/linux-media/msg79078.html I assume this refers to the same hardware. The official freescale driver for that hardware is horrendous. If you are writing code for unrelated hardware, then you should move over to vb2 yourself. videobuf should not be used anymore for new drivers. 4) I still do not entirely understand the control flow and I will have to take another look. I'll see if I can do that tomorrow. Regards, Hans On 09/23/2014 05:11 AM, chen.f...@freescale.com wrote: > Hans, > Do you have any more comment on this patch? > > Best regards, > Fancy Fang > > -Original Message- > From: Fang Chen-B47543 > Sent: Wednesday, September 10, 2014 3:29 PM > To: 'Hans Verkuil'; m.che...@samsung.com; v...@zeniv.linux.org.uk > Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; > linux-kernel@vger.kernel.org; Marek Szyprowski > Subject: RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() > with remap_pfn_range(). > > On the Freescale imx6 platform which belongs to ARM architecture. The driver > is our local v4l2 output driver which is not upstream yet unfortunately. > > Best regards, > Fancy Fang > > -Original Message- > From: Hans Verkuil [mailto:hverk...@xs4all.nl] > Sent: Wednesday, September 10, 2014 3:21 PM > To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk > Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; > linux-kernel@vger.kernel.org; Marek Szyprowski > Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() > with remap_pfn_range(). > > On 09/10/14 09:14, chen.f...@freescale.com wrote: >> It is not a theoretically issue, it is a real case that the mapping failed >> issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel. >> So I need your confirmation on it. > > With which driver does this happen? On which architecture? > > Regards, > > Hans > >> >> Thanks. >> >> Best regards, >> Fancy Fang >> >> -Original Message- >> From: Hans Verkuil [mailto:hverk...@xs4all.nl] >> Sent: Wednesday, September 10, 2014 3:01 PM >> To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk >> Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; >> linux-kernel@vger.kernel.org; Marek Szyprowski >> Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() >> with remap_pfn_range(). >> >> On 09/10/14 07:28, Fancy Fang wrote: >>> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core >>> will assign the corresponding offset to the 'boff' field of the >>> videobuf_buffer for each requested buffer sequentially. Later, user >>> may call mmap() to map one or all of the buffers with the 'offset' >>> parameter which is equal to its 'boff' value. Obviously, the 'offset' >>> value is only used to find the matched buffer instead of to be the >>> real offset from the buffer's physical start address as used by >>> vm_iomap_memory(). So, in some case that if the offset is not zero, >>> vm_iomap_memory() will fail. >> >> Is this just a fix for something that can fail theoretically, or do you >> actually have a case where this happens? I am very reluctant to make any >> changes to videobuf. Drivers should all migrate to vb2. >> >> I have CC-ed Marek as well since he knows a lot more about this stuff than I >> do. >> >> Regards, >> >> Hans >> >>> >>> Signed-off-by: Fancy Fang >>> --- >>> drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++- >>> 1 file changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c >>> b/drivers/media/v4l2-core/videobuf-dma-contig.c >>> index bf80f0f..8bd9889 100644 >>> --- a/drivers/media/v4l2-core/videobuf-dma-contig.c >>> +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c >>> @@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue >>> *q, >&
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Hi Fancy Fang,
I do have a few comments:
1) One reason why the switch to vm_iomap_memory() was made originally was that
that function did a bunch of sanity checks. Since this patch moves back to
remap_pfn_range() those sanity checks are lost and should be reinstated.
2) You need Marek's Ack as well since he understands the memory code much
better than I do.
3) There are efforts underway to make a modern i.mx6 video driver based on
vb2 and all the other modern V4L2 APIs, wouldn't it be much better if freescale
jumps on board and starts working on that code as well? See e.g. this mail
thread: http://www.spinics.net/lists/linux-media/msg79078.html
I assume this refers to the same hardware. The official freescale driver
for that hardware is horrendous.
If you are writing code for unrelated hardware, then you should move over to
vb2 yourself. videobuf should not be used anymore for new drivers.
4) I still do not entirely understand the control flow and I will have to take
another look. I'll see if I can do that tomorrow.
Regards,
Hans
On 09/23/2014 05:11 AM, chen.f...@freescale.com wrote:
Hans,
Do you have any more comment on this patch?
Best regards,
Fancy Fang
-Original Message-
From: Fang Chen-B47543
Sent: Wednesday, September 10, 2014 3:29 PM
To: 'Hans Verkuil'; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On the Freescale imx6 platform which belongs to ARM architecture. The driver
is our local v4l2 output driver which is not upstream yet unfortunately.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:21 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 09:14, chen.f...@freescale.com wrote:
It is not a theoretically issue, it is a real case that the mapping failed
issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
So I need your confirmation on it.
With which driver does this happen? On which architecture?
Regards,
Hans
Thanks.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:01 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make any
changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff than I
do.
Regards,
Hans
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
*q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
- retval = vm_iomap_memory(vma, mem-dma_handle, size);
+ retval = remap_pfn_range(vma, vma-vm_start,
+mem-dma_handle PAGE_SHIFT,
+size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo
RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Thanks a lot, Hans. I know the reason that you use vm_iomap_memory() instead of remap_pfn_range(). But according to my analysis, the sanity check is not suitable for v4l2 buffers mapping. You can check the code logic to see this. Migration to vb2 is not a quick job and it is not on our schedule yet. I just need you to check the code logic and make a decision for this. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Tuesday, September 23, 2014 2:10 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). Hi Fancy Fang, I do have a few comments: 1) One reason why the switch to vm_iomap_memory() was made originally was that that function did a bunch of sanity checks. Since this patch moves back to remap_pfn_range() those sanity checks are lost and should be reinstated. 2) You need Marek's Ack as well since he understands the memory code much better than I do. 3) There are efforts underway to make a modern i.mx6 video driver based on vb2 and all the other modern V4L2 APIs, wouldn't it be much better if freescale jumps on board and starts working on that code as well? See e.g. this mail thread: http://www.spinics.net/lists/linux-media/msg79078.html I assume this refers to the same hardware. The official freescale driver for that hardware is horrendous. If you are writing code for unrelated hardware, then you should move over to vb2 yourself. videobuf should not be used anymore for new drivers. 4) I still do not entirely understand the control flow and I will have to take another look. I'll see if I can do that tomorrow. Regards, Hans On 09/23/2014 05:11 AM, chen.f...@freescale.com wrote: Hans, Do you have any more comment on this patch? Best regards, Fancy Fang -Original Message- From: Fang Chen-B47543 Sent: Wednesday, September 10, 2014 3:29 PM To: 'Hans Verkuil'; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On the Freescale imx6 platform which belongs to ARM architecture. The driver is our local v4l2 output driver which is not upstream yet unfortunately. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Wednesday, September 10, 2014 3:21 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On 09/10/14 09:14, chen.f...@freescale.com wrote: It is not a theoretically issue, it is a real case that the mapping failed issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel. So I need your confirmation on it. With which driver does this happen? On which architecture? Regards, Hans Thanks. Best regards, Fancy Fang -Original Message- From: Hans Verkuil [mailto:hverk...@xs4all.nl] Sent: Wednesday, September 10, 2014 3:01 PM To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org; linux-kernel@vger.kernel.org; Marek Szyprowski Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range(). On 09/10/14 07:28, Fancy Fang wrote: When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core will assign the corresponding offset to the 'boff' field of the videobuf_buffer for each requested buffer sequentially. Later, user may call mmap() to map one or all of the buffers with the 'offset' parameter which is equal to its 'boff' value. Obviously, the 'offset' value is only used to find the matched buffer instead of to be the real offset from the buffer's physical start address as used by vm_iomap_memory(). So, in some case that if the offset is not zero, vm_iomap_memory() will fail. Is this just a fix for something that can fail theoretically, or do you actually have a case where this happens? I am very reluctant to make any changes to videobuf. Drivers should all migrate to vb2. I have CC-ed Marek as well since he knows a lot more about this stuff than I do. Regards, Hans Signed-off-by: Fancy Fang chen.f...@freescale.com --- drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c b/drivers/media/v4l2-core/videobuf-dma-contig.c index bf80f0f..8bd9889 100644 --- a/drivers/media/v4l2-core/videobuf-dma
RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Hans,
Do you have any more comment on this patch?
Best regards,
Fancy Fang
-Original Message-
From: Fang Chen-B47543
Sent: Wednesday, September 10, 2014 3:29 PM
To: 'Hans Verkuil'; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On the Freescale imx6 platform which belongs to ARM architecture. The driver is
our local v4l2 output driver which is not upstream yet unfortunately.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:21 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 09:14, chen.f...@freescale.com wrote:
> It is not a theoretically issue, it is a real case that the mapping failed
> issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
> So I need your confirmation on it.
With which driver does this happen? On which architecture?
Regards,
Hans
>
> Thanks.
>
> Best regards,
> Fancy Fang
>
> -Original Message-
> From: Hans Verkuil [mailto:hverk...@xs4all.nl]
> Sent: Wednesday, September 10, 2014 3:01 PM
> To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
> Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
> linux-kernel@vger.kernel.org; Marek Szyprowski
> Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
> with remap_pfn_range().
>
> On 09/10/14 07:28, Fancy Fang wrote:
>> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
>> will assign the corresponding offset to the 'boff' field of the
>> videobuf_buffer for each requested buffer sequentially. Later, user
>> may call mmap() to map one or all of the buffers with the 'offset'
>> parameter which is equal to its 'boff' value. Obviously, the 'offset'
>> value is only used to find the matched buffer instead of to be the
>> real offset from the buffer's physical start address as used by
>> vm_iomap_memory(). So, in some case that if the offset is not zero,
>> vm_iomap_memory() will fail.
>
> Is this just a fix for something that can fail theoretically, or do you
> actually have a case where this happens? I am very reluctant to make any
> changes to videobuf. Drivers should all migrate to vb2.
>
> I have CC-ed Marek as well since he knows a lot more about this stuff than I
> do.
>
> Regards,
>
> Hans
>
>>
>> Signed-off-by: Fancy Fang
>> ---
>> drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
>> b/drivers/media/v4l2-core/videobuf-dma-contig.c
>> index bf80f0f..8bd9889 100644
>> --- a/drivers/media/v4l2-core/videobuf-dma-contig.c
>> +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
>> @@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
>> *q,
>> /* Try to remap memory */
>> size = vma->vm_end - vma->vm_start;
>> vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
>> -retval = vm_iomap_memory(vma, mem->dma_handle, size);
>> +retval = remap_pfn_range(vma, vma->vm_start,
>> + mem->dma_handle >> PAGE_SHIFT,
>> + size, vma->vm_page_prot);
>> if (retval) {
>> dev_err(q->dev, "mmap: remap failed with error %d. ",
>> retval);
>>
>
--
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RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
Hans,
Do you have any more comment on this patch?
Best regards,
Fancy Fang
-Original Message-
From: Fang Chen-B47543
Sent: Wednesday, September 10, 2014 3:29 PM
To: 'Hans Verkuil'; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On the Freescale imx6 platform which belongs to ARM architecture. The driver is
our local v4l2 output driver which is not upstream yet unfortunately.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:21 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 09:14, chen.f...@freescale.com wrote:
It is not a theoretically issue, it is a real case that the mapping failed
issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
So I need your confirmation on it.
With which driver does this happen? On which architecture?
Regards,
Hans
Thanks.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:01 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make any
changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff than I
do.
Regards,
Hans
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
*q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
-retval = vm_iomap_memory(vma, mem-dma_handle, size);
+retval = remap_pfn_range(vma, vma-vm_start,
+ mem-dma_handle PAGE_SHIFT,
+ size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
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the body of a message to majord...@vger.kernel.org
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Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
It is not a theoretically issue, it is a real case that the mapping failed
issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
So I need your confirmation on it.
Thanks.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:01 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 07:28, Fancy Fang wrote:
> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
> will assign the corresponding offset to the 'boff' field of the
> videobuf_buffer for each requested buffer sequentially. Later, user
> may call mmap() to map one or all of the buffers with the 'offset'
> parameter which is equal to its 'boff' value. Obviously, the 'offset'
> value is only used to find the matched buffer instead of to be the
> real offset from the buffer's physical start address as used by
> vm_iomap_memory(). So, in some case that if the offset is not zero,
> vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make any
changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff than I do.
Regards,
Hans
>
> Signed-off-by: Fancy Fang
> ---
> drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
> b/drivers/media/v4l2-core/videobuf-dma-contig.c
> index bf80f0f..8bd9889 100644
> --- a/drivers/media/v4l2-core/videobuf-dma-contig.c
> +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
> @@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
> *q,
> /* Try to remap memory */
> size = vma->vm_end - vma->vm_start;
> vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> - retval = vm_iomap_memory(vma, mem->dma_handle, size);
> + retval = remap_pfn_range(vma, vma->vm_start,
> + mem->dma_handle >> PAGE_SHIFT,
> + size, vma->vm_page_prot);
> if (retval) {
> dev_err(q->dev, "mmap: remap failed with error %d. ",
> retval);
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On the Freescale imx6 platform which belongs to ARM architecture. The driver is
our local v4l2 output driver which is not upstream yet unfortunately.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:21 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 09:14, chen.f...@freescale.com wrote:
> It is not a theoretically issue, it is a real case that the mapping failed
> issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
> So I need your confirmation on it.
With which driver does this happen? On which architecture?
Regards,
Hans
>
> Thanks.
>
> Best regards,
> Fancy Fang
>
> -Original Message-
> From: Hans Verkuil [mailto:hverk...@xs4all.nl]
> Sent: Wednesday, September 10, 2014 3:01 PM
> To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
> Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
> linux-kernel@vger.kernel.org; Marek Szyprowski
> Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
> with remap_pfn_range().
>
> On 09/10/14 07:28, Fancy Fang wrote:
>> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
>> will assign the corresponding offset to the 'boff' field of the
>> videobuf_buffer for each requested buffer sequentially. Later, user
>> may call mmap() to map one or all of the buffers with the 'offset'
>> parameter which is equal to its 'boff' value. Obviously, the 'offset'
>> value is only used to find the matched buffer instead of to be the
>> real offset from the buffer's physical start address as used by
>> vm_iomap_memory(). So, in some case that if the offset is not zero,
>> vm_iomap_memory() will fail.
>
> Is this just a fix for something that can fail theoretically, or do you
> actually have a case where this happens? I am very reluctant to make any
> changes to videobuf. Drivers should all migrate to vb2.
>
> I have CC-ed Marek as well since he knows a lot more about this stuff than I
> do.
>
> Regards,
>
> Hans
>
>>
>> Signed-off-by: Fancy Fang
>> ---
>> drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
>> b/drivers/media/v4l2-core/videobuf-dma-contig.c
>> index bf80f0f..8bd9889 100644
>> --- a/drivers/media/v4l2-core/videobuf-dma-contig.c
>> +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
>> @@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
>> *q,
>> /* Try to remap memory */
>> size = vma->vm_end - vma->vm_start;
>> vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
>> -retval = vm_iomap_memory(vma, mem->dma_handle, size);
>> +retval = remap_pfn_range(vma, vma->vm_start,
>> + mem->dma_handle >> PAGE_SHIFT,
>> + size, vma->vm_page_prot);
>> if (retval) {
>> dev_err(q->dev, "mmap: remap failed with error %d. ",
>> retval);
>>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On 09/10/14 09:14, chen.f...@freescale.com wrote:
> It is not a theoretically issue, it is a real case that the mapping failed
> issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
> So I need your confirmation on it.
With which driver does this happen? On which architecture?
Regards,
Hans
>
> Thanks.
>
> Best regards,
> Fancy Fang
>
> -Original Message-
> From: Hans Verkuil [mailto:hverk...@xs4all.nl]
> Sent: Wednesday, September 10, 2014 3:01 PM
> To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
> Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
> linux-kernel@vger.kernel.org; Marek Szyprowski
> Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
> with remap_pfn_range().
>
> On 09/10/14 07:28, Fancy Fang wrote:
>> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
>> will assign the corresponding offset to the 'boff' field of the
>> videobuf_buffer for each requested buffer sequentially. Later, user
>> may call mmap() to map one or all of the buffers with the 'offset'
>> parameter which is equal to its 'boff' value. Obviously, the 'offset'
>> value is only used to find the matched buffer instead of to be the
>> real offset from the buffer's physical start address as used by
>> vm_iomap_memory(). So, in some case that if the offset is not zero,
>> vm_iomap_memory() will fail.
>
> Is this just a fix for something that can fail theoretically, or do you
> actually have a case where this happens? I am very reluctant to make any
> changes to videobuf. Drivers should all migrate to vb2.
>
> I have CC-ed Marek as well since he knows a lot more about this stuff than I
> do.
>
> Regards,
>
> Hans
>
>>
>> Signed-off-by: Fancy Fang
>> ---
>> drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
>> b/drivers/media/v4l2-core/videobuf-dma-contig.c
>> index bf80f0f..8bd9889 100644
>> --- a/drivers/media/v4l2-core/videobuf-dma-contig.c
>> +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
>> @@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
>> *q,
>> /* Try to remap memory */
>> size = vma->vm_end - vma->vm_start;
>> vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
>> -retval = vm_iomap_memory(vma, mem->dma_handle, size);
>> +retval = remap_pfn_range(vma, vma->vm_start,
>> + mem->dma_handle >> PAGE_SHIFT,
>> + size, vma->vm_page_prot);
>> if (retval) {
>> dev_err(q->dev, "mmap: remap failed with error %d. ",
>> retval);
>>
>
--
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More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On 09/10/14 07:28, Fancy Fang wrote:
> When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
> will assign the corresponding offset to the 'boff' field of the
> videobuf_buffer for each requested buffer sequentially. Later, user
> may call mmap() to map one or all of the buffers with the 'offset'
> parameter which is equal to its 'boff' value. Obviously, the 'offset'
> value is only used to find the matched buffer instead of to be the
> real offset from the buffer's physical start address as used by
> vm_iomap_memory(). So, in some case that if the offset is not zero,
> vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make
any changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff
than I do.
Regards,
Hans
>
> Signed-off-by: Fancy Fang
> ---
> drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
> b/drivers/media/v4l2-core/videobuf-dma-contig.c
> index bf80f0f..8bd9889 100644
> --- a/drivers/media/v4l2-core/videobuf-dma-contig.c
> +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
> @@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
> *q,
> /* Try to remap memory */
> size = vma->vm_end - vma->vm_start;
> vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> - retval = vm_iomap_memory(vma, mem->dma_handle, size);
> + retval = remap_pfn_range(vma, vma->vm_start,
> + mem->dma_handle >> PAGE_SHIFT,
> + size, vma->vm_page_prot);
> if (retval) {
> dev_err(q->dev, "mmap: remap failed with error %d. ",
> retval);
>
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Signed-off-by: Fancy Fang
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma->vm_end - vma->vm_start;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- retval = vm_iomap_memory(vma, mem->dma_handle, size);
+ retval = remap_pfn_range(vma, vma->vm_start,
+mem->dma_handle >> PAGE_SHIFT,
+size, vma->vm_page_prot);
if (retval) {
dev_err(q->dev, "mmap: remap failed with error %d. ",
retval);
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
- retval = vm_iomap_memory(vma, mem-dma_handle, size);
+ retval = remap_pfn_range(vma, vma-vm_start,
+mem-dma_handle PAGE_SHIFT,
+size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
1.9.1
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make
any changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff
than I do.
Regards,
Hans
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
*q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
- retval = vm_iomap_memory(vma, mem-dma_handle, size);
+ retval = remap_pfn_range(vma, vma-vm_start,
+ mem-dma_handle PAGE_SHIFT,
+ size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On 09/10/14 09:14, chen.f...@freescale.com wrote:
It is not a theoretically issue, it is a real case that the mapping failed
issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
So I need your confirmation on it.
With which driver does this happen? On which architecture?
Regards,
Hans
Thanks.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:01 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make any
changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff than I
do.
Regards,
Hans
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
*q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
-retval = vm_iomap_memory(vma, mem-dma_handle, size);
+retval = remap_pfn_range(vma, vma-vm_start,
+ mem-dma_handle PAGE_SHIFT,
+ size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
On the Freescale imx6 platform which belongs to ARM architecture. The driver is
our local v4l2 output driver which is not upstream yet unfortunately.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:21 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 09:14, chen.f...@freescale.com wrote:
It is not a theoretically issue, it is a real case that the mapping failed
issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
So I need your confirmation on it.
With which driver does this happen? On which architecture?
Regards,
Hans
Thanks.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:01 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make any
changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff than I
do.
Regards,
Hans
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
*q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
-retval = vm_iomap_memory(vma, mem-dma_handle, size);
+retval = remap_pfn_range(vma, vma-vm_start,
+ mem-dma_handle PAGE_SHIFT,
+ size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
It is not a theoretically issue, it is a real case that the mapping failed
issue happens in 3.14.y kernel but not happens in previous 3.10.y kernel.
So I need your confirmation on it.
Thanks.
Best regards,
Fancy Fang
-Original Message-
From: Hans Verkuil [mailto:hverk...@xs4all.nl]
Sent: Wednesday, September 10, 2014 3:01 PM
To: Fang Chen-B47543; m.che...@samsung.com; v...@zeniv.linux.org.uk
Cc: Guo Shawn-R65073; linux-me...@vger.kernel.org;
linux-kernel@vger.kernel.org; Marek Szyprowski
Subject: Re: [PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory()
with remap_pfn_range().
On 09/10/14 07:28, Fancy Fang wrote:
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Is this just a fix for something that can fail theoretically, or do you
actually have a case where this happens? I am very reluctant to make any
changes to videobuf. Drivers should all migrate to vb2.
I have CC-ed Marek as well since he knows a lot more about this stuff than I do.
Regards,
Hans
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue
*q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
- retval = vm_iomap_memory(vma, mem-dma_handle, size);
+ retval = remap_pfn_range(vma, vma-vm_start,
+ mem-dma_handle PAGE_SHIFT,
+ size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Signed-off-by: Fancy Fang
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma->vm_end - vma->vm_start;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- retval = vm_iomap_memory(vma, mem->dma_handle, size);
+ retval = remap_pfn_range(vma, vma->vm_start,
+mem->dma_handle >> PAGE_SHIFT,
+size, vma->vm_page_prot);
if (retval) {
dev_err(q->dev, "mmap: remap failed with error %d. ",
retval);
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
- retval = vm_iomap_memory(vma, mem-dma_handle, size);
+ retval = remap_pfn_range(vma, vma-vm_start,
+mem-dma_handle PAGE_SHIFT,
+size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
1.9.1
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Signed-off-by: Fancy Fang
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma->vm_end - vma->vm_start;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- retval = vm_iomap_memory(vma, mem->dma_handle, size);
+ retval = remap_pfn_range(vma, vma->vm_start,
+mem->dma_handle >> PAGE_SHIFT,
+size, vma->vm_page_prot);
if (retval) {
dev_err(q->dev, "mmap: remap failed with error %d. ",
retval);
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] [media] videobuf-dma-contig: replace vm_iomap_memory() with remap_pfn_range().
When user requests V4L2_MEMORY_MMAP type buffers, the videobuf-core
will assign the corresponding offset to the 'boff' field of the
videobuf_buffer for each requested buffer sequentially. Later, user
may call mmap() to map one or all of the buffers with the 'offset'
parameter which is equal to its 'boff' value. Obviously, the 'offset'
value is only used to find the matched buffer instead of to be the
real offset from the buffer's physical start address as used by
vm_iomap_memory(). So, in some case that if the offset is not zero,
vm_iomap_memory() will fail.
Signed-off-by: Fancy Fang chen.f...@freescale.com
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c
b/drivers/media/v4l2-core/videobuf-dma-contig.c
index bf80f0f..8bd9889 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -305,7 +305,9 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
/* Try to remap memory */
size = vma-vm_end - vma-vm_start;
vma-vm_page_prot = pgprot_noncached(vma-vm_page_prot);
- retval = vm_iomap_memory(vma, mem-dma_handle, size);
+ retval = remap_pfn_range(vma, vma-vm_start,
+mem-dma_handle PAGE_SHIFT,
+size, vma-vm_page_prot);
if (retval) {
dev_err(q-dev, mmap: remap failed with error %d. ,
retval);
--
1.9.1
--
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