drm/amd/display: Fix deadlock with display during hanged ring recovery. (f7c8930d) · Commits · 戴 / test

When ring hang happens amdgpu_dm_commit_planes during flip is holding the BO reserved and then stack waiting for fences to signal in reservation_object_wait_timeout_rcu (which won't signal because there was a hnag). Then when we try to shutdown display block during reset recovery from drm_atomic_helper_suspend we also try to reserve the BO from dm_plane_helper_cleanup_fb ending in deadlock. Also remove useless WARN_ON Signed-off-by:

Andrey Grodzovsky <andrey.grodzovsky@amd.com> Reviewed-by:

Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by:

Alex Deucher <alexander.deucher@amd.com>

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

+13 −6

Original line number	Diff line number	Diff line
		@@ -4698,14 +4698,21 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
		*/
		abo = gem_to_amdgpu_bo(fb->obj[0]);
		r = amdgpu_bo_reserve(abo, true);
		if (unlikely(r != 0)) {
		if (unlikely(r != 0))
		DRM_ERROR("failed to reserve buffer before flip\n");
		WARN_ON(1);
		}

		/* Wait for all fences on this FB */
		WARN_ON(reservation_object_wait_timeout_rcu(abo->tbo.resv, true, false,
		MAX_SCHEDULE_TIMEOUT) < 0);
		/*
		* Wait for all fences on this FB. Do limited wait to avoid
		* deadlock during GPU reset when this fence will not signal
		* but we hold reservation lock for the BO.
		*/
		r = reservation_object_wait_timeout_rcu(abo->tbo.resv,
		true, false,
		msecs_to_jiffies(5000));
		if (unlikely(r == 0))
		DRM_ERROR("Waiting for fences timed out.");



		amdgpu_bo_get_tiling_flags(abo, &tiling_flags);

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