On 23/05/18 12:30, Ezequiel Garcia wrote:
> On Tue, 2018-05-22 at 13:55 +0200, Hans Verkuil wrote:
>> On 21/05/18 18:59, Ezequiel Garcia wrote:
>>> From: Gustavo Padovan <[email protected]>
>>>
>>> Now that we've introduced the V4L2_FMT_FLAG_UNORDERED flag,
>>> mark the appropriate formats.
>>>
>>> v2: Set unordered flag before calling the driver callback.
>>>
>>> Signed-off-by: Gustavo Padovan <[email protected]>
>>> Signed-off-by: Ezequiel Garcia <[email protected]>
>>> ---
>>>  drivers/media/v4l2-core/v4l2-ioctl.c | 74 
>>> +++++++++++++++++++++++++++---------
>>>  1 file changed, 57 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c 
>>> b/drivers/media/v4l2-core/v4l2-ioctl.c
>>> index f48c505550e0..2135ac235a96 100644
>>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
>>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
>>> @@ -1102,6 +1102,27 @@ static int v4l_enumoutput(const struct 
>>> v4l2_ioctl_ops *ops,
>>>     return ops->vidioc_enum_output(file, fh, p);
>>>  }
>>>  
>>> +static void v4l_fill_unordered_fmtdesc(struct v4l2_fmtdesc *fmt)
>>> +{
>>> +   switch (fmt->pixelformat) {
>>> +   case V4L2_PIX_FMT_MPEG:
>>> +   case V4L2_PIX_FMT_H264:
>>> +   case V4L2_PIX_FMT_H264_NO_SC:
>>> +   case V4L2_PIX_FMT_H264_MVC:
>>> +   case V4L2_PIX_FMT_H263:
>>> +   case V4L2_PIX_FMT_MPEG1:
>>> +   case V4L2_PIX_FMT_MPEG2:
>>> +   case V4L2_PIX_FMT_MPEG4:
>>> +   case V4L2_PIX_FMT_XVID:
>>> +   case V4L2_PIX_FMT_VC1_ANNEX_G:
>>> +   case V4L2_PIX_FMT_VC1_ANNEX_L:
>>> +   case V4L2_PIX_FMT_VP8:
>>> +   case V4L2_PIX_FMT_VP9:
>>> +   case V4L2_PIX_FMT_HEVC:
>>> +           fmt->flags |= V4L2_FMT_FLAG_UNORDERED;
>>
>> Please add a break here. This prevents potential future errors if new cases
>> are added below this line.
>>
> 
> Sure.
> 
>>> +   }
>>> +}
>>> +
>>>  static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>>>  {
>>>     const unsigned sz = sizeof(fmt->description);
>>> @@ -1310,61 +1331,80 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc 
>>> *fmt)
>>>  
>>>     if (descr)
>>>             WARN_ON(strlcpy(fmt->description, descr, sz) >= sz);
>>> -   fmt->flags = flags;
>>> +   fmt->flags |= flags;
>>>  }
>>>  
>>> -static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
>>> -                           struct file *file, void *fh, void *arg)
>>> -{
>>> -   struct v4l2_fmtdesc *p = arg;
>>> -   int ret = check_fmt(file, p->type);
>>>  
>>> -   if (ret)
>>> -           return ret;
>>> -   ret = -EINVAL;
>>> +static int __vidioc_enum_fmt(const struct v4l2_ioctl_ops *ops,
>>> +                        struct v4l2_fmtdesc *p,
>>> +                        struct file *file, void *fh)
>>> +{
>>> +   int ret = 0;
>>>  
>>>     switch (p->type) {
>>>     case V4L2_BUF_TYPE_VIDEO_CAPTURE:
>>>             if (unlikely(!ops->vidioc_enum_fmt_vid_cap))
>>>                     break;
>>> -           ret = ops->vidioc_enum_fmt_vid_cap(file, fh, arg);
>>> +           ret = ops->vidioc_enum_fmt_vid_cap(file, fh, p);
>>>             break;
>>>     case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
>>>             if (unlikely(!ops->vidioc_enum_fmt_vid_cap_mplane))
>>>                     break;
>>> -           ret = ops->vidioc_enum_fmt_vid_cap_mplane(file, fh, arg);
>>> +           ret = ops->vidioc_enum_fmt_vid_cap_mplane(file, fh, p);
>>>             break;
>>>     case V4L2_BUF_TYPE_VIDEO_OVERLAY:
>>>             if (unlikely(!ops->vidioc_enum_fmt_vid_overlay))
>>>                     break;
>>> -           ret = ops->vidioc_enum_fmt_vid_overlay(file, fh, arg);
>>> +           ret = ops->vidioc_enum_fmt_vid_overlay(file, fh, p);
>>>             break;
>>>     case V4L2_BUF_TYPE_VIDEO_OUTPUT:
>>>             if (unlikely(!ops->vidioc_enum_fmt_vid_out))
>>>                     break;
>>> -           ret = ops->vidioc_enum_fmt_vid_out(file, fh, arg);
>>> +           ret = ops->vidioc_enum_fmt_vid_out(file, fh, p);
>>>             break;
>>>     case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
>>>             if (unlikely(!ops->vidioc_enum_fmt_vid_out_mplane))
>>>                     break;
>>> -           ret = ops->vidioc_enum_fmt_vid_out_mplane(file, fh, arg);
>>> +           ret = ops->vidioc_enum_fmt_vid_out_mplane(file, fh, p);
>>>             break;
>>>     case V4L2_BUF_TYPE_SDR_CAPTURE:
>>>             if (unlikely(!ops->vidioc_enum_fmt_sdr_cap))
>>>                     break;
>>> -           ret = ops->vidioc_enum_fmt_sdr_cap(file, fh, arg);
>>> +           ret = ops->vidioc_enum_fmt_sdr_cap(file, fh, p);
>>>             break;
>>>     case V4L2_BUF_TYPE_SDR_OUTPUT:
>>>             if (unlikely(!ops->vidioc_enum_fmt_sdr_out))
>>>                     break;
>>> -           ret = ops->vidioc_enum_fmt_sdr_out(file, fh, arg);
>>> +           ret = ops->vidioc_enum_fmt_sdr_out(file, fh, p);
>>>             break;
>>>     case V4L2_BUF_TYPE_META_CAPTURE:
>>>             if (unlikely(!ops->vidioc_enum_fmt_meta_cap))
>>>                     break;
>>> -           ret = ops->vidioc_enum_fmt_meta_cap(file, fh, arg);
>>> +           ret = ops->vidioc_enum_fmt_meta_cap(file, fh, p);
>>>             break;
>>>     }
>>> +   return ret;
>>> +}
>>> +
>>> +static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
>>> +                           struct file *file, void *fh, void *arg)
>>> +{
>>> +   struct v4l2_fmtdesc *p = arg;
>>> +   int ret = check_fmt(file, p->type);
>>> +
>>> +   if (ret)
>>> +           return ret;
>>> +   ret = -EINVAL;
>>
>> Why set ret when it is overwritten below?
>>
> 
> Oops, seems to be some leftover code.
> 
>>> +
>>> +   ret = __vidioc_enum_fmt(ops, p, file, fh);
>>> +   if (ret)
>>> +           return ret;
>>
>> Huh? Why call the driver twice? As far as I can see you can just drop
>> these three lines above.
>>
>>
> 
> Well, because I thought this was the outcome of v9 [1]. Let me quote you:
> 
> ""
> I realized that this is a problem since this function is called *after*
> the driver. So the driver has no chance to clear this flag if it knows
> that the queue is always ordered.
> ""
> 
> So, we first call the driver to get struct v4l2_fmtdesc pixelformat field
> filled by the driver, then we call v4l_fill_unordered_fmtdesc()
> to set FLAG_UNORDERED if needed, and finally we call the driver again
> so it can clear the FLAG_UNORDERED.
> 
> Does that make sense?

Not what I meant. v4l_fill_unordered_fmtdesc() should be called first, then
the driver (which can now fiddle with the flag if it wants to) and finally
v4l_fill_fmtdesc(p) is called.

Drivers that support these compressed formats need to be checked though:
they shouldn't overwrite flags unconditionally.

Regards,

        Hans

> 
> [1] https://lkml.org/lkml/2018/5/7/349
> 

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