[PATCH] Revert "drm/amd: Keep display off while going into S4"

[Alex Deucher]

On Thu, May 22, 2025 at 10:13 AM Mario Limonciello
<mario.limonciello at amd.com> wrote:
>
> commit 68bfdc8dc0a1a ("drm/amd: Keep display off while going into S4")
> attempted to keep displays off during the S4 sequence by not resuming
> display IP.  This however leads to hangs because DRM clients such as the
> console can try to access registers and cause a hang.
>
> Cc: stable at vger.kernel.org
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4155
> Fixes: 68bfdc8dc0a1a ("drm/amd: Keep display off while going into S4")
> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 -----
>  1 file changed, 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 7d0687695645..c876f78618cf 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -3469,11 +3469,6 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
>
>                 return 0;
>         }
> -
> -       /* leave display off for S4 sequence */
> -       if (adev->in_s4)
> -               return 0;
> -
>         /* Recreate dc_state - DC invalidates it when setting power state to S3. */
>         dc_state_release(dm_state->context);
>         dm_state->context = dc_state_create(dm->dc, NULL);
> --
> 2.49.0
>