From: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Date: Thu, 16 Mar 2017 15:51:00 -0400
Subject: drm/amd/display: Fix the NULL pointer. (v2)
Git-commit: 53d35dc60d386cdf1d04a318dc010524bf5607a3
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

ret value in amdgpu_dm_atomic_check was not rest to EINVAL
after drm_atomic_add_affected_planes and by this making
any subsequent validation failure pass when returning
to atomic_check.

v2: Add WARN_ON print for dc_commit_streams in
amdgpu_dm_atomic_commit_tail since this should never
fail.

Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Reviewed-by: Andrey Grodzovsky <Andrey.Grodzovsky@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_types.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_types.c
@@ -2392,7 +2392,7 @@ void amdgpu_dm_atomic_commit_tail(
 	}
 
 	/* DC is optimized not to do anything if 'streams' didn't change. */
-	dc_commit_streams(dm->dc, commit_streams, commit_streams_count);
+	WARN_ON(!dc_commit_streams(dm->dc, commit_streams, commit_streams_count));
 
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		struct amdgpu_crtc *acrtc = to_amdgpu_crtc(crtc);
@@ -2858,6 +2858,8 @@ int amdgpu_dm_atomic_check(struct drm_de
 		ret = drm_atomic_add_affected_planes(state, crtc);
 		if (ret)
 			return ret;
+
+		ret = -EINVAL;
 	}
 
 	for (i = 0; i < set_count; i++) {