From 31e9cabe80735803566f270442254b3b52280735 Mon Sep 17 00:00:00 2001 From: "Leo (Sunpeng) Li" Date: Wed, 1 Nov 2017 16:49:14 -0400 Subject: [PATCH 2809/4131] drm/amd/display: Fix warnings on S3 resume This is a followup to the following revert: Rex Zhu Revert "drm/amd/display: Match actual state during S3 resume." Three things needed to be addressed: 1. Potential memory leak on dc_state creation in atomic_check during s3 resume 2. Warnings are now seen in dmesg during S3 resume 3. Since dc_state is now created in atomic_check, what the reverted patch was addressing needs to be reevaluated. This change addresses the above: 1. Since the suspend procedure calls drm_atomic_state_clear, our hook for releasing the dc_state is called. This frees it before atomic_check creates it during resume. The leak does not occur. 2. The dc_crtc/plane_state references kept by the atomic states need to be released before calling atomic_check, which warns if they are non-null. This is because atomic_check is responsible for creating the dc_*_states. This is a special case for S3 resume, since the atomic state duplication that occurs during suspend also copies a reference to the dc_*_states. 3. See 2. comments are also updated to reflect this. Reviewed-by: Andrey Grodzovsky Signed-off-by: Leo (Sunpeng) Li Reviewed-by: Harry Wentland Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 28 +++++++++++++++++++++++ 1 file changed, 28 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 fbff613..66812ba 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -666,6 +666,11 @@ int amdgpu_dm_display_resume(struct amdgpu_device *adev) struct drm_connector *connector; struct drm_crtc *crtc; struct drm_crtc_state *new_crtc_state; + struct dm_crtc_state *dm_new_crtc_state; + struct drm_plane *plane; + struct drm_plane_state *new_plane_state; + struct dm_plane_state *dm_new_plane_state; + int ret = 0; int i; @@ -712,6 +717,29 @@ int amdgpu_dm_display_resume(struct amdgpu_device *adev) #endif new_crtc_state->active_changed = true; + /* + * atomic_check is expected to create the dc states. We need to release + * them here, since they were duplicated as part of the suspend + * procedure. + */ + for_each_new_crtc_in_state(adev->dm.cached_state, crtc, new_crtc_state, i) { + dm_new_crtc_state = to_dm_crtc_state(new_crtc_state); + if (dm_new_crtc_state->stream) { + WARN_ON(kref_read(&dm_new_crtc_state->stream->refcount) > 1); + dc_stream_release(dm_new_crtc_state->stream); + dm_new_crtc_state->stream = NULL; + } + } + + for_each_new_plane_in_state(adev->dm.cached_state, plane, new_plane_state, i) { + dm_new_plane_state = to_dm_plane_state(new_plane_state); + if (dm_new_plane_state->dc_state) { + WARN_ON(kref_read(&dm_new_plane_state->dc_state->refcount) > 1); + dc_plane_state_release(dm_new_plane_state->dc_state); + dm_new_plane_state->dc_state = NULL; + } + } + ret = drm_atomic_helper_resume(ddev, adev->dm.cached_state); #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0) && !defined(OS_NAME_RHEL_7_4) -- 2.7.4