[U-Boot] [PATCH] mmc:sdhci: Fix card ready status timeout.

[Przemyslaw Marczak]

On 08/29/2013 05:16 AM, Jaehoon Chung wrote:
> Hi Przemyslaw,
>
> Could you give me the test-case?
> I want to test this problem.
>
> On 08/29/2013 01:49 AM, Przemyslaw Marczak wrote:
>> According to JEDEC eMMC specification, after data transfer
>> (multiple or single block) host must wait for card ready
>> status. This is done by waiting for command and data lines
>> to be at idle state after transfer. JEDEC does not specify
>> maximum timeout.
>>
>> Before this change max timeout was 10 ms but in case of UMS
>> - when system do multiple read/write operations on random
>> card blocks - timeout causes I/O errors.
>> The timeout has been increased to 200ms after data transfer.
>> For other transfers it stays unchanged.
>>
>> Tested on Goni and Trats.
>>
>> Signed-off-by: Przemyslaw Marczak <p.marczak at samsung.com>
>> Cc: Pantelis Antoniou <panto at antoniou-consulting.com>


Hello,

You can ease reproduce this problem by typing "ums" on prompt(Trats).
If you are using Goni (without ums config), the problem is hard to 
reproduce in this case. Sometimes read one block from mmc just after 
start causes error and then you can see information "Controller never
released inhibit bit(s)".
Patch will be completed with some code comment.

Thank you

-- 
Przemyslaw Marczak
Samsung R&D Institute Poland
Samsung Electronics
p.marczak at samsung.com