[PATCH] drm/bridge: lt9211: Add null pointer check for LT9211

[Chenyuan Yang]

drm_atomic_get_new_connector_for_encoder and
drm_atomic_get_new_connector_state could return Null.
Thus, add the null pointer check for them with a similar format with
lt9611_bridge_atomic_enable in LT9611.

Signed-off-by: Chenyuan Yang <chenyuan0y at gmail.com>
---
 drivers/gpu/drm/bridge/lontium-lt9211.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9211.c b/drivers/gpu/drm/bridge/lontium-lt9211.c
index 9b2dac9bd63c..6be30c8bdf15 100644
--- a/drivers/gpu/drm/bridge/lontium-lt9211.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9211.c
@@ -463,6 +463,7 @@ static void lt9211_atomic_enable(struct drm_bridge *bridge,
 	const struct drm_crtc_state *crtc_state;
 	const struct drm_display_mode *mode;
 	struct drm_connector *connector;
+	struct drm_connector_state *conn_state;
 	struct drm_crtc *crtc;
 	bool lvds_format_24bpp;
 	bool lvds_format_jeida;
@@ -516,8 +517,18 @@ static void lt9211_atomic_enable(struct drm_bridge *bridge,
 	 */
 	connector = drm_atomic_get_new_connector_for_encoder(state,
 							     bridge->encoder);
-	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
+	if (WARN_ON(!connector))
+		return;
+
+	conn_state = drm_atomic_get_new_connector_state(state, connector);
+	if (WARN_ON(!conn_state))
+		return;
+
+	crtc = conn_state->crtc;
 	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+	if (WARN_ON(!crtc_state))
+		return;
+
 	mode = &crtc_state->adjusted_mode;
 
 	ret = lt9211_read_chipid(ctx);
-- 
2.34.1