Re: mmc0: error -95 doing runtime resume

[Bart Van Assche <bvanassche@acm.org>]

On 2/21/25 7:41 AM, Thomas Haschka wrote:
> Bug Fix: block: Improve stability of SD cards in Microsoft Surface GO 2 and
>               possibly other devices.
> 
> 
> The commit 65a558f66c308
>      block: Improve performance for BLK_MQ_F_BLOCKING drivers
> 
> basically made the use of SD cards in my Microsoft Surface GO 2 impossible.
> The cards do stop functioning after about 15 minutes. Mostly at io 
> intensive
> tasks.
> 
> As outlined in https://bugzilla.kernel.org/show_bug.cgi?id=218821
> i bisected the problem that yielded an unstable operation of the cardreader
> on my Surface GO 2.
> I successfully reversed the commit 65a558f66c308 in 6.12.16 using
> the attached patch. As I suppose the bug introduced with this commit might
> hit other users of sd-cards in similar hardware I suggest this commit shall
> be reversed, even if the improved performance might be gone.

Thank you for having bisected this issue and for having shared the
result of the bisection process. This is very useful information.

Since the commit mentioned above is about 1.5 years old and has not
caused any issues for anyone who is not using an SD card reader, that
commit is probably not the root cause of the reported behavior. Are SD
cards controlled by the MMC driver? If so, I think the next step is to
take a close look at the MMC driver. I have Cc-ed the MMC driver maintainer.

Bart.