disp: msm: dp: Add null check for payload allocation

Adds null check for payload allocation to prevent calling
mst helper functions with a null payload.

Change-Id: I63951eec7714bbf00ff7c968ea4e6b1ced9a29e3
Signed-off-by: Nisarg Bhavsar <[email protected]>

msm/dp/dp_mst_drm.c

@@ -512,6 +512,12 @@ static void _dp_mst_update_timeslots(struct dp_mst_private *mst,
 	mst_state = to_drm_dp_mst_topology_state(mst->mst_mgr.base.state);
 	payload = drm_atomic_get_mst_payload_state(mst_state, port);
 
+	if (!payload) {
+		DP_ERR("mst bridge [%d] update_timeslots failed, null payload\n",
+				mst_bridge->id);
+		return;
+	}
+
 	for (i = 0; i < MAX_DP_MST_DRM_BRIDGES; i++) {
 		dp_bridge = &mst->mst_bridge[i];
 		if (mst_bridge == dp_bridge) {
@@ -645,7 +651,7 @@ static int _dp_mst_bridge_pre_enable_part1(struct dp_mst_bridge *dp_bridge)
 #if (KERNEL_VERSION(6, 1, 0) <= LINUX_VERSION_CODE)
 	mst_state = to_drm_dp_mst_topology_state(mst->mst_mgr.base.state);
 	payload = drm_atomic_get_mst_payload_state(mst_state, port);
-	if (payload->time_slots <= 0) {
+	if (!payload || payload->time_slots <= 0) {
 		DP_ERR("time slots not allocated for conn:%d\n", DP_MST_CONN_ID(dp_bridge));
 		rc = -EINVAL;
 		goto end;
@@ -694,6 +700,12 @@ static void _dp_mst_bridge_pre_enable_part2(struct dp_mst_bridge *dp_bridge)
 	mst_state = to_drm_dp_mst_topology_state(mst->mst_mgr.base.state);
 	payload = drm_atomic_get_mst_payload_state(mst_state, port);
 
+	if (!payload) {
+		DP_ERR("mst bridge [%d] _pre enable part-2 failed, null payload\n",
+				dp_bridge->id);
+		return;
+	}
+
 	mst->mst_fw_cbs->update_payload_part2(&mst->mst_mgr, mst_state->base.state, payload);
 #else
 	mst->mst_fw_cbs->update_payload_part2(&mst->mst_mgr);
@@ -725,6 +737,13 @@ static void _dp_mst_bridge_pre_disable_part1(struct dp_mst_bridge *dp_bridge)
 #if (KERNEL_VERSION(6, 1, 0) <= LINUX_VERSION_CODE)
 	mst_state = to_drm_dp_mst_topology_state(mst->mst_mgr.base.state);
 	payload = drm_atomic_get_mst_payload_state(mst_state, port);
+
+	if (!payload) {
+		DP_ERR("mst bridge [%d] _pre disable part-1 failed, null payload\n",
+				dp_bridge->id);
+		return;
+	}
+
 #if (KERNEL_VERSION(6, 1, 25) <= LINUX_VERSION_CODE)
 	mst->mst_fw_cbs->reset_vcpi_slots(&mst->mst_mgr, mst_state, payload, payload);
 #else