[PATCH] drm/msm/mdp5: Add check for kzalloc

[Jiasheng Jiang]

As kzalloc may fail and return NULL pointer,
it should be better to check the return value
in order to avoid the NULL pointer dereference.

Fixes: 1cff7440a86e ("drm/msm: Convert to using __drm_atomic_helper_crtc_reset() for reset.")
Signed-off-by: Jiasheng Jiang <jiasheng at iscas.ac.cn>
---
 drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
index e86421c69bd1..86036dd4e1e8 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
@@ -1139,7 +1139,10 @@ static void mdp5_crtc_reset(struct drm_crtc *crtc)
 	if (crtc->state)
 		mdp5_crtc_destroy_state(crtc, crtc->state);
 
-	__drm_atomic_helper_crtc_reset(crtc, &mdp5_cstate->base);
+	if (mdp5_cstate)
+		__drm_atomic_helper_crtc_reset(crtc, &mdp5_cstate->base);
+	else
+		__drm_atomic_helper_crtc_reset(crtc, NULL);
 }
 
 static const struct drm_crtc_funcs mdp5_crtc_no_lm_cursor_funcs = {
-- 
2.25.1