drm/dp_mst: Reset message rx state after OOM in drm_dp_mst_handle_up_req()

After an out-of-memory error the reception state should be reset, so
that the next attempt receiving a message doesn't fail (due to getting a
start-of-message packet, while the reception state has already the
start-of-message flag set).

Cc: Lyude Paul <[email protected]>
Reviewed-by: Lyude Paul <[email protected]>
Signed-off-by: Imre Deak <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: ideak

drivers/gpu/drm/display/drm_dp_mst_topology.c

@@ -4110,6 +4110,7 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 {
 	struct drm_dp_pending_up_req *up_req;
 	struct drm_dp_mst_branch *mst_primary;
+	int ret = 0;
 
 	if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
 		goto out_clear_reply;
@@ -4118,8 +4119,10 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 		return 0;
 
 	up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
-	if (!up_req)
-		return -ENOMEM;
+	if (!up_req) {
+		ret = -ENOMEM;
+		goto out_clear_reply;
+	}
 
 	INIT_LIST_HEAD(&up_req->next);
 
@@ -4186,7 +4189,7 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 	drm_dp_mst_topology_put_mstb(mst_primary);
 out_clear_reply:
 	memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
-	return 0;
+	return ret;
 }
 
 static void update_msg_rx_state(struct drm_dp_mst_topology_mgr *mgr)