Re: [RESEND PATCH v2 0/1] mmc: dw_mmc: Fix UHS tuning on some brand of cards.

[Jaehoon Chung <jh80.chung@samsung.com>]

Hi Enric,

On 06/20/2016 04:59 PM, Enric Balletbo Serra wrote:
> Hi Jaehoon,
> 
> 2016-04-27 10:53 GMT+02:00 Enric Balletbo i Serra
> <enric.balletbo@collabora.com>:
>>
>>
>> On 27/04/16 10:35, Jaehoon Chung wrote:
>>> On 04/26/2016 05:03 PM, Enric Balletbo i Serra wrote:
>>>> Hi,
>>>>
>>>> I introduced the cover letter to give some background about this.
>>>>
>>>> I have been investigating a problem related to at least one specific sdcard when
>>>> UHS-I is set. The card is not detected due the tuning phase reports a
>>>> failure. Since the problem is only reproduced with a single model of a single
>>>> brand of card, it is probably a card firmware issue, but the card works fine
>>>> on my laptop.
>>>
>>> I think you have analyzed many case..of course..it was successful to switch voltage, right?
>>> Maybe this patch too old..so can you remember which specific sdcard is produced?
>>>
>>
>> Yes it was successful to switch voltage. The specific card is an UNIREX 16GB Class 10
>> SD card (Compatible with UHS-1)
>>
> 
> Any feedback for this patch?

Sorry..I missed this patch..Thanks for reminding!
I will check this patch as soon as possible.

Best Regards,
Jaehoon Chung

> 
> 
>>>>
>>>> The first attempt to fix this was a patch sent by Doug Anderson [1], but Alim
>>>> Akhtar found that this produced randomly a hung task on Peach-pi. I can confirm
>>>> that it's easy to reproduce the hung task, either, with cold boots or suspend to
>>>> ram tests.
>>>
>>> Yep..I have already tested and checked for this.
>>>
>>>>
>>>> I tried to fix both problems (the original issue and the one introduced by the
>>>> patch) in different ways, but I ended thinking that this second proposal is the
>>>> most simple that solves both issues. So let's try to fix this by handling the
>>>> response CRC error slightly differently when tuning command is happening.
>>>>
>>>> I tested the patch on both platforms, on exynos and on rockhip. I did lots of
>>>> tests and at the moment the patch seems to fix the rockchip issue and don't
>>>> hung on exynos. I'll continue testing meanwhile we discuss about it.
>>>>
>>>> I think the patch, at least, needs the Doug's approval (as he dig into the issue
>>>> before) and the Tested-by Alim. So will be good if you have a slot of time to
>>>> look a bit into this.
>>>>
>>>> Thanks in advance.
>>>>  Enric
>>>>
>>>> [1] https://lkml.org/lkml/2015/5/18/495
>>>>
>>>> Changelog since v1:
>>>> - Fix the issue found by Alim with exynos letting the data transfer
>>>>   take place only when MMC_SEND_TUNING_BLOCK is issued.
>>>>
>>>> Doug Anderson (1):
>>>>   mmc: dw_mmc: Wait for data transfer after response errors.
>>>>
>>>>  drivers/mmc/host/dw_mmc.c | 27 +++++++++++++++++++++++++++
>>>>  1 file changed, 27 insertions(+)
>>>>
>>>
> 
> 
>