Regression from 3c196f056666 ("drm/amdgpu: always reset the asic in suspend (v2)") on suspend?

[Alex Deucher]

On Sat, Feb 12, 2022 at 1:23 PM Salvatore Bonaccorso <carnil at debian.org> wrote:
>
> Hi Alex, hi all
>
> In Debian we got a regression report from Dominique Dumont, CC'ed in
> https://bugs.debian.org/1005005 that afer an update to 5.15.15 based
> kernel, his machine noe longer suspends correctly, after screen going
> black as usual it comes back. The Debian bug above contians a trace.
>
> Dominique confirmed that this issue persisted after updating to 5.16.7
> furthermore he bisected the issue and found
>
>         3c196f05666610912645c7c5d9107706003f67c3 is the first bad commit
>         commit 3c196f05666610912645c7c5d9107706003f67c3
>         Author: Alex Deucher <alexander.deucher at amd.com>
>         Date:   Fri Nov 12 11:25:30 2021 -0500
>
>             drm/amdgpu: always reset the asic in suspend (v2)
>
>             [ Upstream commit daf8de0874ab5b74b38a38726fdd3d07ef98a7ee ]
>
>             If the platform suspend happens to fail and the power rail
>             is not turned off, the GPU will be in an unknown state on
>             resume, so reset the asic so that it will be in a known
>             good state on resume even if the platform suspend failed.
>
>             v2: handle s0ix
>
>             Acked-by: Luben Tuikov <luben.tuikov at amd.com>
>             Acked-by: Evan Quan <evan.quan at amd.com>
>             Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>             Signed-off-by: Sasha Levin <sashal at kernel.org>
>
>          drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 5 ++++-
>          1 file changed, 4 insertions(+), 1 deletion(-)
>
> to be the first bad commit, see https://bugs.debian.org/1005005#34 .
>
> Does this ring any bell? Any idea on the problem?

Does the system actually suspend?  Putting the GPU into reset on
suspend shouldn't cause any problems since the power rail will
presumably be cut by the platform.  Is this system S0i3 or regular S3?
 Does this patch help by any chance?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e55a3aea418269266d84f426b3bd70794d3389c8

Alex


>
> Regards,
> Salvatore