Re: WARNING: CPU: 0 PID: 1271 at drivers/mmc/core/core.c:991 mmc_release_host+0xa0/0xa8

[John Stultz]

On Fri, Aug 12, 2016 at 1:30 AM, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote:
> If special req meets, mrq_pre and mrq_cur are both null after schedule
> queue. And for this special req, host->claimed is released. For the
> next req peeking from blk, we run into mmc_get_card again which means
> we should never meet this WARN when releasing host. So it's
> interesting to dig out actually what is happening there...
>
> But at least for dw_mmc-rockchip, we have been using this feature,
> ERASE/Trim/discard, for years. I didn't see it ever. Anyway from the
> code I was reading, I don't think it should be issue of this commit.
>
> Please look at this regression report I saw.
>
> https://lkml.org/lkml/2016/8/11/130

Hrm. Unfortunately I was still able to trigger the issue with the fix
from that mail.

thanks
-john