From: "Leo (Sunpeng) Li" <sunpeng.li@amd.com>
Date: Thu, 7 Sep 2017 17:05:38 -0400
Subject: drm/amd/display: Match actual state during S3 resume.
Git-commit: 4f346e655d24140fb40b46f814506ba17ac34ea1
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

During system suspend, we:

1. Cache a duplicate of the current DRM atomic state, which calls hooks
   to duplicate our internal states.
2. Call hooks to disable all functionalities.
3. System suspended.

During resume, we attempt to restore the cached state. However, our
interal states are now stale, since step 1 was done before step 2.
i.e. our cached state does not reflect the disabled nature of things.

This change resolves that by destroying all relevant states to reflect
the actual state during resume.

Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |   36 ++++++++++++++++++++++
 1 file changed, 36 insertions(+)

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -648,6 +648,11 @@ int amdgpu_dm_display_resume(struct amdg
 	struct drm_connector *connector;
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *new_crtc_state;
+	struct dm_crtc_state *dm_crtc_state;
+	struct drm_plane *plane;
+	struct drm_plane_state *plane_state;
+	struct dm_plane_state *dm_plane_state;
+	struct dm_atomic_state *cached_state;
 	int ret = 0;
 	int i;
 
@@ -686,6 +691,37 @@ int amdgpu_dm_display_resume(struct amdg
 	for_each_new_crtc_in_state(adev->dm.cached_state, crtc, new_crtc_state, i)
 		new_crtc_state->active_changed = true;
 
+	cached_state = to_dm_atomic_state(adev->dm.cached_state);
+
+	/*
+	 * During suspend, the cached state is saved before all streams are
+	 * disabled. Refresh cached state to match actual current state before
+	 * restoring it.
+	 */
+	WARN_ON(kref_read(&cached_state->context->refcount) > 1);
+	dc_release_state(cached_state->context);
+
+	cached_state->context = dc_create_state();
+	dc_resource_state_copy_construct_current(adev->dm.dc, cached_state->context);
+
+	for_each_new_crtc_in_state(adev->dm.cached_state, crtc, new_crtc_state, i) {
+		dm_crtc_state = to_dm_crtc_state(new_crtc_state);
+		if (dm_crtc_state->stream) {
+			WARN_ON(kref_read(&dm_crtc_state->stream->refcount) > 1);
+			dc_stream_release(dm_crtc_state->stream);
+			dm_crtc_state->stream = NULL;
+		}
+	}
+
+	for_each_new_plane_in_state(adev->dm.cached_state, plane, plane_state, i) {
+		dm_plane_state = to_dm_plane_state(plane_state);
+		if (dm_plane_state->dc_state) {
+			WARN_ON(kref_read(&dm_plane_state->dc_state->refcount) > 1);
+			dc_plane_state_release(dm_plane_state->dc_state);
+			dm_plane_state->dc_state = NULL;
+		}
+	}
+
 	ret = drm_atomic_helper_resume(ddev, adev->dm.cached_state);
 
 	drm_atomic_state_put(adev->dm.cached_state);