drm/amd/display: Fix ISM dc_lock deadlock during suspend

Browse source

[Why]
System hang observed during suspend/resume while video is playing.
amdgpu_dm_ism_disable() is called under dc_lock and waits for ISM
delayed work via disable_delayed_work_sync(). The work handlers
themselves take dc_lock, producing an ABBA deadlock when a worker is
in flight at suspend time.

[How]
Split the disable path into two phases with opposite locking
contracts:
  1. amdgpu_dm_ism_disable() -- quiesces workers, must NOT hold
     dc_lock.
  2. amdgpu_dm_ism_force_full_power() (new) -- drives the ISM FSM
     back to FULL_POWER_RUNNING, must hold dc_lock.

Reviewed-by: Sun peng (Leo) Li <sunpeng.li@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

...

This commit is contained in:

Ray Wu 2026-04-30 10:08:16 +08:00 • committed by Alex Deucher

parent e91130c016

commit 3714fe2425

3 changed files with 70 additions and 12 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

25

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

View file

56

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_ism.c

View file

1

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_ism.h

View file