Am 2020-10-21 17:04, schrieb Ulf Hansson:
On Fri, 16 Oct 2020 at 14:50, Michael Walle <michael@xxxxxxxx> wrote:
Am 2020-10-16 12:53, schrieb Ulf Hansson:
> On Fri, 16 Oct 2020 at 01:12, Michael Walle <michael@xxxxxxxx> wrote:
>>
>> On rare occations there is the following error:
>>
>> mmc0: Tuning timeout, falling back to fixed sampling clock
>>
>> There are SD cards which takes a significant longer time to reply to
>> the
>> first CMD19 command. The eSDHC takes the data timeout value into
>> account
>> during the tuning period. The SDHCI core doesn't explicitly set this
>> timeout for the tuning procedure. Thus on the slow cards, there might
>> be
>> a spurious "Buffer Read Ready" interrupt, which in turn triggers a
>> wrong
>> sequence of events. In the end this will lead to an unsuccessful
>> tuning
>> procedure and to the above error.
>>
>> To workaround this, set the timeout to the maximum value (which is the
>> best we can do) and the SDHCI core will take care of the proper
>> timeout
>> handling.
>>
>> Signed-off-by: Michael Walle <michael@xxxxxxxx>
>
> Sound like this should be tagged for stable, right?
Yes, but I was unsure about that. I didn't find a lot of Fixes: tags
in
the history of this driver (eg. for errata etc.)
I could repost a v2 with a fixes tag if you like.
If this is regression and you can point to a specific commit it fixes,
then please yes!
That would be commit ba49cbd0936e ("mmc: sdhci-of-esdhc: add tuning
support"). But as of today it isn't much left of that original code.
So I don't know if adding that fixes tag will help a lot. Correct me
if I'm wrong.
-michael
