drm/amd/pm: fix race in power state check before mutex lock

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The power state check in amdgpu_dpm_set_powergating_by_smu() is done
before acquiring the pm mutex, leading to a race condition where:
1. Thread A checks state and thinks no change is needed
2. Thread B acquires mutex and modifies the state
3. Thread A returns without updating state, causing inconsistency

Fix this by moving the mutex lock before the power state check,
ensuring atomicity of the state check and modification.

Fixes: 6ee27ee27b ("drm/amd/pm: avoid duplicate powergate/ungate setting")
Signed-off-by: Yang Wang <kevinyang.wang@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7a3fbdfd19)

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Yang Wang 2026-01-27 11:07:07 +08:00 • committed by Alex Deucher

parent 8b1ecc9377

commit ee8d07cd57

1 changed files with 4 additions and 3 deletions

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drivers/gpu/drm/amd/pm/amdgpu_dpm.c

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