Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-09 Thread Hans de Goede 

Hi,

On 08-09-15 17:38, Yousong Zhou wrote:

I just tried a method from allwinner's u-boot sources: retry the mode switch in
case of an error [1].  It was accompanied with a comment quoted below:

//retry for Toshiba emmc;for the first time Toshiba emmc change to HS
//it will return response crc err,so retry

Well, that 1GB card of mine is labeled as "pqi" made in Korea.  This workaround
really worked and it succeeded on the second try, though I am not sure how
anti-spec this can be (the spec says a power reset SHOULD be done in the case
of crc error in the status data).

The above change alone can make the card work.  I also noticed that allwinner's
uboot will disable the clock first before setting it and re-enable it
thereafter [2].  I can only guess that this is possibly some bugfix made
by engineers of allwinner.  So I mimicked this approach and attached a patch
here.


Thanks for this. So if I understand you correctly then just the:

"mmc: retry in the case of failing to switch to HS mode"

Patch is enough to make things work, right ?

That makes sense because the clock dance you are subscribing is something which
allwinner does in many places and it really is not necessary.

Can you do a similar patch for the kernel and test that too ?

And once you've a working kernel patch submit that to Ulf, with the mmc
list in the Cc?

If Ulf is willing to take this fix on the kernel side (I'm the sunxi-mmc 
maintainer
in the kernel, and the fix will get my ack), then I'm willing to take the u-boot
version of this fix.

Regards,

Hans

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Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-08 Thread Yousong Zhou 
On 7 September 2015 at 15:02, Hans de Goede  wrote:
> Hi,
>
>
> On 06-09-15 16:47, Yousong Zhou wrote:
>>
>> On Sep 6, 2015 10:14 PM, "Shawn Lin"  wrote:
>>>
>>>
>>> 在 2015/9/6 20:09, Yousong Zhou 写道:


 Hi,

 On 6 September 2015 at 08:12, Shawn Lin 
 wrote:
>
>
> On 2015/9/5 22:58, Hans de Goede wrote:
>>
>>
>>
>> Hi Shawn Lin,
>>
>> On 05-09-15 16:07, Shawn Lin wrote:
>>>
>>>
>>>
>>> On 2015/9/5 18:19, Yousong Zhou wrote:



 A SD card with sunxi-mmc can fail with the following error message
 (RCD for
 response CRC error) when trying to switch to highspeed mode.
 Setting
 the bus
 clock before the access mode switch fixed it.
>>>
>>>
>>>
>>>
>>> No, that's wrong!
>>>
>>> Before this card is switched to highspeed, it works under
>>> identification mode(From spec: bus clock <= 400KHz). How could you
>>> raise bus clock to higher clk rate which I _guess_ is 52MHz before
>>> you
>>> notify sd cards to run into highspeed mode?
>>>
>>> Althought it works for this card, this patch will not please the
>>> other
>>> cards that they might not reply CMDs any longer including the
>>> following CMD6.
>>
>>
>>
>>
>> Thanks for the feedback, this is exactly why I asked Yousong Zhou to
>> take this
>> to the mmc list.
>>
>> So if this is not the proper fix for the problem that Yousong Zhou is
>> seeing, then
>> what might be the proper fix ?
>>
>
>   From my knowledge of mmc, there hadn't have a way to deal with this
>>
>> "broken"
>
> case. In another word, IMO,it's ANTI-SPEC. We can't be too spec
>>
>> sometimes,
>
> but at least we shouldn't violate it.
>

 Maybe the fix is anti-spec.  But the fact is that the card works on
 many other platforms with the builtin card reader (not through an USB
 adapter), including Mac OS X, my old Nokia Symbian phone, and Windows.

>> Could it be that the sunxi-mmc is doing some things in the wrong order
>> when
>> changing the clock, or is this all under control of the mmc core ?
>>
>
> all of this is under control of the mmc core.
> So if Yongsong does want this card to work for any linux-based mmc
>>
>> stack, I
>
> guess something like that should be "better"?
>
> if (switch to HS fail) {
>   set_bus_clk
>   goto retry switch to HS
> }
>
> BUT...I admit it seems strange as well.
>

 The SD Specification (simplified version) says "If CRC error occurs on
 the status data, the host should issue a power cycle.", so I guess the
 above approach is anti-spec in some way :)

>>>
>>> Right，I was guessing that way from your intention.
>>>
>>>
 In case it may help debug this problem, I'd like to add that the card
 previously worked fine with U-Boot before commit [1].  This can also
 be confirmed by Debian Jessie installer image with which the old
 U-Boot there worked fine while the kernel (3.16) did not.

[1] sunxi: mmc: Properly setup mod-clk and clock sampling phases,

>>
>> http://git.denx.de/?p=u-boot.git;a=commit;h=fc3a832576ce7bb597b1823935bfb7dcca235c3c
>
>
> Interesting, one thing that patch does is introduce a switch from parent pll
> when switching from 400KHz to higher clocks. Can you try the attached patch
> ?
>
> If reverting u-boot commit fc3a832576ce7bb597b1823935bfb7dcca235c3c fixes
> things, then it is probably best to focus on fixing u-boot first, and then
> we can likely apply the same fix to the kernel.
>

I just tried a method from allwinner's u-boot sources: retry the mode switch in
case of an error [1].  It was accompanied with a comment quoted below:

//retry for Toshiba emmc;for the first time Toshiba emmc change to HS
//it will return response crc err,so retry

Well, that 1GB card of mine is labeled as "pqi" made in Korea.  This workaround
really worked and it succeeded on the second try, though I am not sure how
anti-spec this can be (the spec says a power reset SHOULD be done in the case
of crc error in the status data).

The above change alone can make the card work.  I also noticed that allwinner's
uboot will disable the clock first before setting it and re-enable it
thereafter [2].  I can only guess that this is possibly some bugfix made
by engineers of allwinner.  So I mimicked this approach and attached a patch
here.

 [1] 
https://github.com/allwinner-zh/bootloader/blob/master/u-boot-2011.09/drivers/mmc/mmc.c#L2220
 [2] 
https://github.com/allwinner-zh/bootloader/blob/master/u-boot-2011.09/drivers/mmc/sunxi_mmc.c#L822

Regards.

yousong

> With which SoC(s) are you seeing this problem ? I believe that there
> may be some differences

Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-07 Thread Hans de Goede 

Hi,

On 06-09-15 16:47, Yousong Zhou wrote:

On Sep 6, 2015 10:14 PM, "Shawn Lin"  wrote:


在 2015/9/6 20:09, Yousong Zhou 写道:


Hi,

On 6 September 2015 at 08:12, Shawn Lin  wrote:


On 2015/9/5 22:58, Hans de Goede wrote:



Hi Shawn Lin,

On 05-09-15 16:07, Shawn Lin wrote:



On 2015/9/5 18:19, Yousong Zhou wrote:



A SD card with sunxi-mmc can fail with the following error message
(RCD for
response CRC error) when trying to switch to highspeed mode.  Setting
the bus
clock before the access mode switch fixed it.




No, that's wrong!

Before this card is switched to highspeed, it works under
identification mode(From spec: bus clock <= 400KHz). How could you
raise bus clock to higher clk rate which I _guess_ is 52MHz before you
notify sd cards to run into highspeed mode?

Althought it works for this card, this patch will not please the other
cards that they might not reply CMDs any longer including the
following CMD6.




Thanks for the feedback, this is exactly why I asked Yousong Zhou to
take this
to the mmc list.

So if this is not the proper fix for the problem that Yousong Zhou is
seeing, then
what might be the proper fix ?



  From my knowledge of mmc, there hadn't have a way to deal with this

"broken"

case. In another word, IMO,it's ANTI-SPEC. We can't be too spec

sometimes,

but at least we shouldn't violate it.



Maybe the fix is anti-spec.  But the fact is that the card works on
many other platforms with the builtin card reader (not through an USB
adapter), including Mac OS X, my old Nokia Symbian phone, and Windows.


Could it be that the sunxi-mmc is doing some things in the wrong order
when
changing the clock, or is this all under control of the mmc core ?



all of this is under control of the mmc core.
So if Yongsong does want this card to work for any linux-based mmc

stack, I

guess something like that should be "better"?

if (switch to HS fail) {
  set_bus_clk
  goto retry switch to HS
}

BUT...I admit it seems strange as well.



The SD Specification (simplified version) says "If CRC error occurs on
the status data, the host should issue a power cycle.", so I guess the
above approach is anti-spec in some way :)



Right，I was guessing that way from your intention.



In case it may help debug this problem, I'd like to add that the card
previously worked fine with U-Boot before commit [1].  This can also
be confirmed by Debian Jessie installer image with which the old
U-Boot there worked fine while the kernel (3.16) did not.

   [1] sunxi: mmc: Properly setup mod-clk and clock sampling phases,


http://git.denx.de/?p=u-boot.git;a=commit;h=fc3a832576ce7bb597b1823935bfb7dcca235c3c


Interesting, one thing that patch does is introduce a switch from parent pll
when switching from 400KHz to higher clocks. Can you try the attached patch ?

If reverting u-boot commit fc3a832576ce7bb597b1823935bfb7dcca235c3c fixes
things, then it is probably best to focus on fixing u-boot first, and then
we can likely apply the same fix to the kernel.

With which SoC(s) are you seeing this problem ? I believe that there
may be some differences between the mmc controller used in the A10/13 vs
later SoCs so this may be a SoC specific issue.

Regards,

Hans



OpenWrt ticket 20387 has more info about the U-Boot failure.

https://dev.openwrt.org/ticket/20387

Anyway, I have no idea what's the effect of those magic numbers on
"sampling phases".  Never played with such things before :)


I happended to fix some problems which seems *similar* to yours(but I'm

not sure just from commit[1]'s msg):


https://patchwork.kernel.org/patch/7119661/


Cheers

  yousong
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Best Regards
Shawn Lin

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>From 1523e6fbd27b5da22b0c3cb4e8eda50bce7562cf Mon Sep 17 00:00:00 2001
From: Hans de Goede 
Date: Mon, 7 Sep 2015 08:56:52 +0200
Subject: [PATCH] sunxi: mmc: Add a delay after changing the PLL to allow clock
 to stabilize

Signed-off-by: Hans de Goede 
---
 drivers/mmc/sunxi_mmc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
index 25f18ad..db3c489 100644
--- a/drivers/mmc/sunxi_mmc.c

Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-07 Thread Yousong Zhou 
Hi

On 7 September 2015 at 15:02, Hans de Goede  wrote:
> Hi,
>
>
> On 06-09-15 16:47, Yousong Zhou wrote:
>>
>> On Sep 6, 2015 10:14 PM, "Shawn Lin"  wrote:
>>>
>>>
>>> 在 2015/9/6 20:09, Yousong Zhou 写道:


 Hi,

 On 6 September 2015 at 08:12, Shawn Lin 
 wrote:
>
>
> On 2015/9/5 22:58, Hans de Goede wrote:
>>
>>
>>
>> Hi Shawn Lin,
>>
>> On 05-09-15 16:07, Shawn Lin wrote:
>>>
>>>
>>>
>>> On 2015/9/5 18:19, Yousong Zhou wrote:



 A SD card with sunxi-mmc can fail with the following error message
 (RCD for
 response CRC error) when trying to switch to highspeed mode.
 Setting
 the bus
 clock before the access mode switch fixed it.
>>>
>>>
>>>
>>>
>>> No, that's wrong!
>>>
>>> Before this card is switched to highspeed, it works under
>>> identification mode(From spec: bus clock <= 400KHz). How could you
>>> raise bus clock to higher clk rate which I _guess_ is 52MHz before
>>> you
>>> notify sd cards to run into highspeed mode?
>>>
>>> Althought it works for this card, this patch will not please the
>>> other
>>> cards that they might not reply CMDs any longer including the
>>> following CMD6.
>>
>>
>>
>>
>> Thanks for the feedback, this is exactly why I asked Yousong Zhou to
>> take this
>> to the mmc list.
>>
>> So if this is not the proper fix for the problem that Yousong Zhou is
>> seeing, then
>> what might be the proper fix ?
>>
>
>   From my knowledge of mmc, there hadn't have a way to deal with this
>>
>> "broken"
>
> case. In another word, IMO,it's ANTI-SPEC. We can't be too spec
>>
>> sometimes,
>
> but at least we shouldn't violate it.
>

 Maybe the fix is anti-spec.  But the fact is that the card works on
 many other platforms with the builtin card reader (not through an USB
 adapter), including Mac OS X, my old Nokia Symbian phone, and Windows.

>> Could it be that the sunxi-mmc is doing some things in the wrong order
>> when
>> changing the clock, or is this all under control of the mmc core ?
>>
>
> all of this is under control of the mmc core.
> So if Yongsong does want this card to work for any linux-based mmc
>>
>> stack, I
>
> guess something like that should be "better"?
>
> if (switch to HS fail) {
>   set_bus_clk
>   goto retry switch to HS
> }
>
> BUT...I admit it seems strange as well.
>

 The SD Specification (simplified version) says "If CRC error occurs on
 the status data, the host should issue a power cycle.", so I guess the
 above approach is anti-spec in some way :)

>>>
>>> Right，I was guessing that way from your intention.
>>>
>>>
 In case it may help debug this problem, I'd like to add that the card
 previously worked fine with U-Boot before commit [1].  This can also
 be confirmed by Debian Jessie installer image with which the old
 U-Boot there worked fine while the kernel (3.16) did not.

[1] sunxi: mmc: Properly setup mod-clk and clock sampling phases,

>>
>> http://git.denx.de/?p=u-boot.git;a=commit;h=fc3a832576ce7bb597b1823935bfb7dcca235c3c
>
>
> Interesting, one thing that patch does is introduce a switch from parent pll
> when switching from 400KHz to higher clocks. Can you try the attached patch
> ?
>

Previously I tried inserting udelay(1000) immediately after many
writel calls: the result were all the same.  I just tried that patch
adding mdelay(100) after mmc_set_mod_clk(), still no luck, the same
error message just as before.

> If reverting u-boot commit fc3a832576ce7bb597b1823935bfb7dcca235c3c fixes
> things, then it is probably best to focus on fixing u-boot first, and then
> we can likely apply the same fix to the kernel.
>
> With which SoC(s) are you seeing this problem ? I believe that there
> may be some differences between the mmc controller used in the A10/13 vs
> later SoCs so this may be a SoC specific issue.

It's a Cubieboard2 with Allwinner A20.

Regards,

yousong

>
> Regards,
>
> Hans
>
>
>
>> OpenWrt ticket 20387 has more info about the U-Boot failure.
>>
>> https://dev.openwrt.org/ticket/20387
>>
>> Anyway, I have no idea what's the effect of those magic numbers on
>> "sampling phases".  Never played with such things before :)
>>
>>> I happended to fix some problems which seems *similar* to yours(but I'm
>>
>> not sure just from commit[1]'s msg):
>>>
>>>
>>> https://patchwork.kernel.org/patch/7119661/
>>>
 Cheers

   yousong
 --
 To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
 the body of a message to majord...@vger.kernel.org
 More majordomo info at

Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-06 Thread Shawn Lin 

On 2015/9/6 22:51, Yousong Zhou wrote:

all of this is under control of the mmc core.
So if Yongsong does want this card to work for any linux-based mmc stack,
I
guess something like that should be "better"?

if (switch to HS fail) {
  set_bus_clk
  goto retry switch to HS
}

BUT...I admit it seems strange as well.



The SD Specification (simplified version) says "If CRC error occurs on
the status data, the host should issue a power cycle.", so I guess the
above approach is anti-spec in some way :)



Right，I was guessing that way from your intention.


In case it may help debug this problem, I'd like to add that the card
previously worked fine with U-Boot before commit [1].  This can also
be confirmed by Debian Jessie installer image with which the old
U-Boot there worked fine while the kernel (3.16) did not.

   [1] sunxi: mmc: Properly setup mod-clk and clock sampling phases,

http://git.denx.de/?p=u-boot.git;a=commit;h=fc3a832576ce7bb597b1823935bfb7dcca235c3c



Interesting... but that at least prove your patch is a workaround but not
find the root cause.

Anyway, look into commit-sha [1], can you have a test by restoring mod-clk
and clock sampling phases before jump to kernel.



Maybe my statement about U-Boot commit [1] above was a little
ambiguous, sorry.  I meant to say that with that commit applied,
U-Boot failed initialising the card the same way as the kernel, i.e.
response crc error.

The Debian Jessie installer image's U-Boot worked fine and booted the
kernel because it was before commit [1] happened.  However after that
the 3.16 kernel failed initialising the card.



So I undertand your point:  Uboot w/o commit[1] + 3.16 kernel failed 
that way just as Uboot w/ commit[1] + pre-3.16 kernel, right?


If that is it, could you check sunxi-platform's patches merged into 
v3.16 for sure whether there is any patch do the same things just like 
what commit[1] did for uboot or not?



So, with commit [1], U-Boot failed right away without any chance at
all jumping to kernel.

OpenWrt ticket 20387 has more info about the U-Boot failure.

https://dev.openwrt.org/ticket/20387

Anyway, I have no idea what's the effect of those magic numbers on
"sampling phases".  Never played with such things before :)

 yousong


I happended to fix some problems which seems *similar* to yours(but I'm not
sure just from commit[1]'s msg):

https://patchwork.kernel.org/patch/7119661/







--
Best Regards
Shawn Lin

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Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-06 Thread Yousong Zhou 
>>> all of this is under control of the mmc core.
>>> So if Yongsong does want this card to work for any linux-based mmc stack,
>>> I
>>> guess something like that should be "better"?
>>>
>>> if (switch to HS fail) {
>>>  set_bus_clk
>>>  goto retry switch to HS
>>> }
>>>
>>> BUT...I admit it seems strange as well.
>>>
>>
>> The SD Specification (simplified version) says "If CRC error occurs on
>> the status data, the host should issue a power cycle.", so I guess the
>> above approach is anti-spec in some way :)
>>
>
> Right，I was guessing that way from your intention.
>
>> In case it may help debug this problem, I'd like to add that the card
>> previously worked fine with U-Boot before commit [1].  This can also
>> be confirmed by Debian Jessie installer image with which the old
>> U-Boot there worked fine while the kernel (3.16) did not.
>>
>>   [1] sunxi: mmc: Properly setup mod-clk and clock sampling phases,
>>
>> http://git.denx.de/?p=u-boot.git;a=commit;h=fc3a832576ce7bb597b1823935bfb7dcca235c3c
>>
>
> Interesting... but that at least prove your patch is a workaround but not
> find the root cause.
>
> Anyway, look into commit-sha [1], can you have a test by restoring mod-clk
> and clock sampling phases before jump to kernel.
>

Maybe my statement about U-Boot commit [1] above was a little
ambiguous, sorry.  I meant to say that with that commit applied,
U-Boot failed initialising the card the same way as the kernel, i.e.
response crc error.

The Debian Jessie installer image's U-Boot worked fine and booted the
kernel because it was before commit [1] happened.  However after that
the 3.16 kernel failed initialising the card.

So, with commit [1], U-Boot failed right away without any chance at
all jumping to kernel.

OpenWrt ticket 20387 has more info about the U-Boot failure.

https://dev.openwrt.org/ticket/20387

Anyway, I have no idea what's the effect of those magic numbers on
"sampling phases".  Never played with such things before :)

yousong

> I happended to fix some problems which seems *similar* to yours(but I'm not
> sure just from commit[1]'s msg):
>
> https://patchwork.kernel.org/patch/7119661/

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Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-06 Thread Shawn Lin 

在 2015/9/6 20:09, Yousong Zhou 写道:

Hi,

On 6 September 2015 at 08:12, Shawn Lin  wrote:

On 2015/9/5 22:58, Hans de Goede wrote:


Hi Shawn Lin,

On 05-09-15 16:07, Shawn Lin wrote:


On 2015/9/5 18:19, Yousong Zhou wrote:


A SD card with sunxi-mmc can fail with the following error message
(RCD for
response CRC error) when trying to switch to highspeed mode.  Setting
the bus
clock before the access mode switch fixed it.



No, that's wrong!

Before this card is switched to highspeed, it works under
identification mode(From spec: bus clock <= 400KHz). How could you
raise bus clock to higher clk rate which I _guess_ is 52MHz before you
notify sd cards to run into highspeed mode?

Althought it works for this card, this patch will not please the other
cards that they might not reply CMDs any longer including the
following CMD6.



Thanks for the feedback, this is exactly why I asked Yousong Zhou to
take this
to the mmc list.

So if this is not the proper fix for the problem that Yousong Zhou is
seeing, then
what might be the proper fix ?



 From my knowledge of mmc, there hadn't have a way to deal with this "broken"
case. In another word, IMO,it's ANTI-SPEC. We can't be too spec sometimes,
but at least we shouldn't violate it.



Maybe the fix is anti-spec.  But the fact is that the card works on
many other platforms with the builtin card reader (not through an USB
adapter), including Mac OS X, my old Nokia Symbian phone, and Windows.


Could it be that the sunxi-mmc is doing some things in the wrong order
when
changing the clock, or is this all under control of the mmc core ?



all of this is under control of the mmc core.
So if Yongsong does want this card to work for any linux-based mmc stack, I
guess something like that should be "better"?

if (switch to HS fail) {
 set_bus_clk
 goto retry switch to HS
}

BUT...I admit it seems strange as well.



The SD Specification (simplified version) says "If CRC error occurs on
the status data, the host should issue a power cycle.", so I guess the
above approach is anti-spec in some way :)



Right，I was guessing that way from your intention.


In case it may help debug this problem, I'd like to add that the card
previously worked fine with U-Boot before commit [1].  This can also
be confirmed by Debian Jessie installer image with which the old
U-Boot there worked fine while the kernel (3.16) did not.

  [1] sunxi: mmc: Properly setup mod-clk and clock sampling phases,
http://git.denx.de/?p=u-boot.git;a=commit;h=fc3a832576ce7bb597b1823935bfb7dcca235c3c



Interesting... but that at least prove your patch is a workaround but 
not find the root cause.


Anyway, look into commit-sha [1], can you have a test by restoring 
mod-clk and clock sampling phases before jump to kernel.


I happended to fix some problems which seems *similar* to yours(but I'm 
not sure just from commit[1]'s msg):


https://patchwork.kernel.org/patch/7119661/


Cheers

 yousong
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--
Best Regards
Shawn Lin

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Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-06 Thread Yousong Zhou 
On Sep 6, 2015 10:14 PM, "Shawn Lin"  wrote:
>
> 在 2015/9/6 20:09, Yousong Zhou 写道:
>>
>> Hi,
>>
>> On 6 September 2015 at 08:12, Shawn Lin  wrote:
>>>
>>> On 2015/9/5 22:58, Hans de Goede wrote:


 Hi Shawn Lin,

 On 05-09-15 16:07, Shawn Lin wrote:
>
>
> On 2015/9/5 18:19, Yousong Zhou wrote:
>>
>>
>> A SD card with sunxi-mmc can fail with the following error message
>> (RCD for
>> response CRC error) when trying to switch to highspeed mode.  Setting
>> the bus
>> clock before the access mode switch fixed it.
>
>
>
> No, that's wrong!
>
> Before this card is switched to highspeed, it works under
> identification mode(From spec: bus clock <= 400KHz). How could you
> raise bus clock to higher clk rate which I _guess_ is 52MHz before you
> notify sd cards to run into highspeed mode?
>
> Althought it works for this card, this patch will not please the other
> cards that they might not reply CMDs any longer including the
> following CMD6.



 Thanks for the feedback, this is exactly why I asked Yousong Zhou to
 take this
 to the mmc list.

 So if this is not the proper fix for the problem that Yousong Zhou is
 seeing, then
 what might be the proper fix ?

>>>
>>>  From my knowledge of mmc, there hadn't have a way to deal with this
"broken"
>>> case. In another word, IMO,it's ANTI-SPEC. We can't be too spec
sometimes,
>>> but at least we shouldn't violate it.
>>>
>>
>> Maybe the fix is anti-spec.  But the fact is that the card works on
>> many other platforms with the builtin card reader (not through an USB
>> adapter), including Mac OS X, my old Nokia Symbian phone, and Windows.
>>
 Could it be that the sunxi-mmc is doing some things in the wrong order
 when
 changing the clock, or is this all under control of the mmc core ?

>>>
>>> all of this is under control of the mmc core.
>>> So if Yongsong does want this card to work for any linux-based mmc
stack, I
>>> guess something like that should be "better"?
>>>
>>> if (switch to HS fail) {
>>>  set_bus_clk
>>>  goto retry switch to HS
>>> }
>>>
>>> BUT...I admit it seems strange as well.
>>>
>>
>> The SD Specification (simplified version) says "If CRC error occurs on
>> the status data, the host should issue a power cycle.", so I guess the
>> above approach is anti-spec in some way :)
>>
>
> Right，I was guessing that way from your intention.
>
>
>> In case it may help debug this problem, I'd like to add that the card
>> previously worked fine with U-Boot before commit [1].  This can also
>> be confirmed by Debian Jessie installer image with which the old
>> U-Boot there worked fine while the kernel (3.16) did not.
>>
>>   [1] sunxi: mmc: Properly setup mod-clk and clock sampling phases,
>>
http://git.denx.de/?p=u-boot.git;a=commit;h=fc3a832576ce7bb597b1823935bfb7dcca235c3c
>>
>
> Interesting... but that at least prove your patch is a workaround but not
find the root cause.
>
> Anyway, look into commit-sha [1], can you have a test by restoring
mod-clk and clock sampling phases before jump to kernel.
>

Maybe my statement about U-Boot commit [1] above was a little ambiguous,
sorry.  I meant to say that with that commit applied, U-Boot failed
initialising the card the same way as the kernel, i.e. response crc error.

The Debian Jessie installer image's U-Boot worked fine and booted the
kernel because it was before commit [1] happened.  However after that the
3.16 kernel failed initialising the card.

So, with commit [1], U-Boot failed right away without any chance at all
jumping to kernel.

OpenWrt ticket 20387 has more info about the U-Boot failure.

https://dev.openwrt.org/ticket/20387

Anyway, I have no idea what's the effect of those magic numbers on
"sampling phases".  Never played with such things before :)

> I happended to fix some problems which seems *similar* to yours(but I'm
not sure just from commit[1]'s msg):
>
> https://patchwork.kernel.org/patch/7119661/
>
>> Cheers
>>
>>  yousong
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majord...@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
>>
>
>
> --
> Best Regards
> Shawn Lin
>
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Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-06 Thread Yousong Zhou 
Hi,

On 6 September 2015 at 08:12, Shawn Lin  wrote:
> On 2015/9/5 22:58, Hans de Goede wrote:
>>
>> Hi Shawn Lin,
>>
>> On 05-09-15 16:07, Shawn Lin wrote:
>>>
>>> On 2015/9/5 18:19, Yousong Zhou wrote:

 A SD card with sunxi-mmc can fail with the following error message
 (RCD for
 response CRC error) when trying to switch to highspeed mode.  Setting
 the bus
 clock before the access mode switch fixed it.
>>>
>>>
>>> No, that's wrong!
>>>
>>> Before this card is switched to highspeed, it works under
>>> identification mode(From spec: bus clock <= 400KHz). How could you
>>> raise bus clock to higher clk rate which I _guess_ is 52MHz before you
>>> notify sd cards to run into highspeed mode?
>>>
>>> Althought it works for this card, this patch will not please the other
>>> cards that they might not reply CMDs any longer including the
>>> following CMD6.
>>
>>
>> Thanks for the feedback, this is exactly why I asked Yousong Zhou to
>> take this
>> to the mmc list.
>>
>> So if this is not the proper fix for the problem that Yousong Zhou is
>> seeing, then
>> what might be the proper fix ?
>>
>
> From my knowledge of mmc, there hadn't have a way to deal with this "broken"
> case. In another word, IMO,it's ANTI-SPEC. We can't be too spec sometimes,
> but at least we shouldn't violate it.
>

Maybe the fix is anti-spec.  But the fact is that the card works on
many other platforms with the builtin card reader (not through an USB
adapter), including Mac OS X, my old Nokia Symbian phone, and Windows.

>> Could it be that the sunxi-mmc is doing some things in the wrong order
>> when
>> changing the clock, or is this all under control of the mmc core ?
>>
>
> all of this is under control of the mmc core.
> So if Yongsong does want this card to work for any linux-based mmc stack, I
> guess something like that should be "better"?
>
> if (switch to HS fail) {
> set_bus_clk
> goto retry switch to HS
> }
>
> BUT...I admit it seems strange as well.
>

The SD Specification (simplified version) says "If CRC error occurs on
the status data, the host should issue a power cycle.", so I guess the
above approach is anti-spec in some way :)

In case it may help debug this problem, I'd like to add that the card
previously worked fine with U-Boot before commit [1].  This can also
be confirmed by Debian Jessie installer image with which the old
U-Boot there worked fine while the kernel (3.16) did not.

 [1] sunxi: mmc: Properly setup mod-clk and clock sampling phases,
http://git.denx.de/?p=u-boot.git;a=commit;h=fc3a832576ce7bb597b1823935bfb7dcca235c3c

Cheers

yousong

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[linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-05 Thread Shawn Lin 

On 2015/9/5 18:19, Yousong Zhou wrote:

A SD card with sunxi-mmc can fail with the following error message (RCD for
response CRC error) when trying to switch to highspeed mode.  Setting the bus
clock before the access mode switch fixed it.


No, that's wrong!

Before this card is switched to highspeed, it works under identification 
mode(From spec: bus clock <= 400KHz). How could you
raise bus clock to higher clk rate which I _guess_ is 52MHz before you 
notify sd cards to run into highspeed mode?


Althought it works for this card, this patch will not please the other 
cards that they might not reply CMDs any longer including the following 
CMD6.





 [1.112060] mmc0: host does not support reading read-only switch, 
assuming write-enable
 [1.120203] ehci-platform 1c1c000.usb: irq 31, io mem 0x01c1c000
 [1.126527] sunxi-mmc 1c0f000.mmc: smc 0 err, cmd 6, RD RCE !!
 [1.132388] sunxi-mmc 1c0f000.mmc: data error, sending stop command
 [1.139451] sunxi-mmc 1c0f000.mmc: send stop command failed
 [1.145056] mmc0: error -110 whilst initialising SD card
 [1.150424] ehci-platform 1c1c000.usb: USB 2.0 started, EHCI 1.00
 [1.156533] sunxi-mmc 1c0f000.mmc: smc 0 err, cmd 1, RTO !!

Signed-off-by: Yousong Zhou 
---
  drivers/mmc/core/sd.c |   10 +-
  1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 4e7366a..402a8db 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -366,6 +366,11 @@ int mmc_sd_switch_hs(struct mmc_card *card)
return -ENOMEM;
}

+   /*
+* Set bus frequency to match highspeed mode.
+*/
+   mmc_set_clock(card->host, mmc_sd_get_max_clock(card));
+
err = mmc_sd_switch(card, 1, 0, 1, status);
if (err)
goto out;
@@ -969,11 +974,6 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
goto free_card;

/*
-* Set bus speed.
-*/
-   mmc_set_clock(host, mmc_sd_get_max_clock(card));
-
-   /*
 * Switch to wider bus (if supported).
 */
if ((host->caps & MMC_CAP_4_BIT_DATA) &&




--
Best Regards
Shawn Lin

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Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-05 Thread Hans de Goede 

Hi Shawn Lin,

On 05-09-15 16:07, Shawn Lin wrote:

On 2015/9/5 18:19, Yousong Zhou wrote:

A SD card with sunxi-mmc can fail with the following error message (RCD for
response CRC error) when trying to switch to highspeed mode.  Setting the bus
clock before the access mode switch fixed it.


No, that's wrong!

Before this card is switched to highspeed, it works under identification mode(From 
spec: bus clock <= 400KHz). How could you
raise bus clock to higher clk rate which I _guess_ is 52MHz before you notify 
sd cards to run into highspeed mode?

Althought it works for this card, this patch will not please the other cards 
that they might not reply CMDs any longer including the following CMD6.


Thanks for the feedback, this is exactly why I asked Yousong Zhou to take this
to the mmc list.

So if this is not the proper fix for the problem that Yousong Zhou is seeing, 
then
what might be the proper fix ?

Could it be that the sunxi-mmc is doing some things in the wrong order when
changing the clock, or is this all under control of the mmc core ?

Regards,

Hans







 [1.112060] mmc0: host does not support reading read-only switch, 
assuming write-enable
 [1.120203] ehci-platform 1c1c000.usb: irq 31, io mem 0x01c1c000
 [1.126527] sunxi-mmc 1c0f000.mmc: smc 0 err, cmd 6, RD RCE !!
 [1.132388] sunxi-mmc 1c0f000.mmc: data error, sending stop command
 [1.139451] sunxi-mmc 1c0f000.mmc: send stop command failed
 [1.145056] mmc0: error -110 whilst initialising SD card
 [1.150424] ehci-platform 1c1c000.usb: USB 2.0 started, EHCI 1.00
 [1.156533] sunxi-mmc 1c0f000.mmc: smc 0 err, cmd 1, RTO !!

Signed-off-by: Yousong Zhou 
---
  drivers/mmc/core/sd.c |   10 +-
  1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 4e7366a..402a8db 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -366,6 +366,11 @@ int mmc_sd_switch_hs(struct mmc_card *card)
  return -ENOMEM;
  }

+/*
+ * Set bus frequency to match highspeed mode.
+ */
+mmc_set_clock(card->host, mmc_sd_get_max_clock(card));
+
  err = mmc_sd_switch(card, 1, 0, 1, status);
  if (err)
  goto out;
@@ -969,11 +974,6 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
  goto free_card;

  /*
- * Set bus speed.
- */
-mmc_set_clock(host, mmc_sd_get_max_clock(card));
-
-/*
   * Switch to wider bus (if supported).
   */
  if ((host->caps & MMC_CAP_4_BIT_DATA) &&






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Re: [linux-sunxi] Re: [RFC] mmc: core: Set clock before switching to highspeed mode.

2015-09-05 Thread Shawn Lin 

On 2015/9/5 22:58, Hans de Goede wrote:

Hi Shawn Lin,

On 05-09-15 16:07, Shawn Lin wrote:

On 2015/9/5 18:19, Yousong Zhou wrote:

A SD card with sunxi-mmc can fail with the following error message
(RCD for
response CRC error) when trying to switch to highspeed mode.  Setting
the bus
clock before the access mode switch fixed it.


No, that's wrong!

Before this card is switched to highspeed, it works under
identification mode(From spec: bus clock <= 400KHz). How could you
raise bus clock to higher clk rate which I _guess_ is 52MHz before you
notify sd cards to run into highspeed mode?

Althought it works for this card, this patch will not please the other
cards that they might not reply CMDs any longer including the
following CMD6.


Thanks for the feedback, this is exactly why I asked Yousong Zhou to
take this
to the mmc list.

So if this is not the proper fix for the problem that Yousong Zhou is
seeing, then
what might be the proper fix ?



From my knowledge of mmc, there hadn't have a way to deal with this 
"broken" case. In another word, IMO,it's ANTI-SPEC. We can't be too spec 
sometimes, but at least we shouldn't violate it.



Could it be that the sunxi-mmc is doing some things in the wrong order when
changing the clock, or is this all under control of the mmc core ?



all of this is under control of the mmc core.
So if Yongsong does want this card to work for any linux-based mmc 
stack, I guess something like that should be "better"?


if (switch to HS fail) {
set_bus_clk
goto retry switch to HS
}

BUT...I admit it seems strange as well.



Regards,

Hans







 [1.112060] mmc0: host does not support reading read-only
switch, assuming write-enable
 [1.120203] ehci-platform 1c1c000.usb: irq 31, io mem 0x01c1c000
 [1.126527] sunxi-mmc 1c0f000.mmc: smc 0 err, cmd 6, RD RCE !!
 [1.132388] sunxi-mmc 1c0f000.mmc: data error, sending stop
command
 [1.139451] sunxi-mmc 1c0f000.mmc: send stop command failed
 [1.145056] mmc0: error -110 whilst initialising SD card
 [1.150424] ehci-platform 1c1c000.usb: USB 2.0 started, EHCI
1.00
 [1.156533] sunxi-mmc 1c0f000.mmc: smc 0 err, cmd 1, RTO !!

Signed-off-by: Yousong Zhou 
---
  drivers/mmc/core/sd.c |   10 +-
  1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 4e7366a..402a8db 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -366,6 +366,11 @@ int mmc_sd_switch_hs(struct mmc_card *card)
  return -ENOMEM;
  }

+/*
+ * Set bus frequency to match highspeed mode.
+ */
+mmc_set_clock(card->host, mmc_sd_get_max_clock(card));
+
  err = mmc_sd_switch(card, 1, 0, 1, status);
  if (err)
  goto out;
@@ -969,11 +974,6 @@ static int mmc_sd_init_card(struct mmc_host
*host, u32 ocr,
  goto free_card;

  /*
- * Set bus speed.
- */
-mmc_set_clock(host, mmc_sd_get_max_clock(card));
-
-/*
   * Switch to wider bus (if supported).
   */
  if ((host->caps & MMC_CAP_4_BIT_DATA) &&











--
Best Regards
Shawn Lin

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