[PATCH] drm/amd/display: fix dereferencing possible ERR_PTR()

[shirish.s@xxxxxxx (Shirish S)]

This patch fixes static checker warning caused by
"36cc549d5986: "drm/amd/display: disable CRTCs with
NULL FB on their primary plane (V2)"

Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Shirish S <shirish.s at amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +++
 1 file changed, 3 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 0564676..9e2cdc9 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4893,6 +4893,9 @@ static int dm_atomic_check_plane_state_fb(struct drm_atomic_state *state,
 			return -EDEADLK;
 
 		crtc_state = drm_atomic_get_crtc_state(plane_state->state, crtc);
+		if (IS_ERR(crtc_state))
+			return PTR_ERR(crtc_state);
+
 		if (crtc->primary == plane && crtc_state->active) {
 			if (!plane_state->fb)
 				return -EINVAL;
-- 
2.7.4