On 8/19/26 00:47, Linkai Gong wrote:
On GPU reset, dm_suspend() takes dc_lock and leaves it for dm_resume() to drop. If amdgpu_dm_commit_zero_streams() or dm_dmub_hw_init() fails, the function returns with the lock still held. The matching resume path is then skipped, so every later dc_lock take hangs.Release the cached DC state and unlock before returning the error. Fixes: 3cf7a0bc87f0 ("drm/amd/display: Catch failures for amdgpu_dm_commit_zero_streams()") Fixes: 2b6943df5413 ("drm/amd/display: Pass up errors for reset GPU that fails to init HW") Cc: [email protected] Signed-off-by: Linkai Gong <[email protected]>
Great finding and fix. I'll get this added to amd-staging-drm-next. Reviewed-by: Mario Limonciello <[email protected]>
--- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++++ 1 file changed, 6 insertions(+) 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 941c1a312824..214aca906fe1 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -3511,6 +3511,9 @@ static int dm_suspend(struct amdgpu_ip_block *ip_block) res = amdgpu_dm_commit_zero_streams(dm->dc); if (res != DC_OK) { drm_err(adev_to_drm(adev), "Failed to commit zero streams: %d\n", res); + dc_state_release(dm->cached_dc_state); + dm->cached_dc_state = NULL; + mutex_unlock(&dm->dc_lock); return -EINVAL; }@@ -3824,6 +3827,9 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)r = dm_dmub_hw_init(adev); if (r) { drm_err(adev_to_drm(adev), "DMUB interface failed to initialize: status=%d\n", r); + dc_state_release(dm->cached_dc_state); + dm->cached_dc_state = NULL; + mutex_unlock(&dm->dc_lock); return r; }
