From: Andrey Grodzovsky Date: Wed, 13 Feb 2019 18:53:45 +0000 (-0500) Subject: drm/amd/display: Fix deadlock with display during hanged ring recovery. X-Git-Tag: v5.15~6763^2~10^2~40 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f7c8930d9e8b188caa53705883373c49f95fd284;p=platform%2Fkernel%2Flinux-starfive.git drm/amd/display: Fix deadlock with display during hanged ring recovery. 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 Reviewed-by: Nicholas Kazlauskas Signed-off-by: Alex Deucher --- 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 ad31d7b..c7b66fa 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -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);