--- a/drivers/firmware/arm_scpi.c	2018-04-28 00:27:06.193482672 +0200
+++ b/drivers/firmware/arm_scpi.c	2018-04-28 01:10:20.073047893 +0200
@@ -555,6 +555,12 @@
 		scpi_process_cmd(scpi_chan, msg->cmd);
 
 	put_scpi_xfer(msg, scpi_chan);
+
+	if ((ret == -ETIME) || (ret == -ETIMEDOUT)) {
+		pr_err("%s: mbox_send_message %hhu via channel%hhu failed: %d\n", __func__,
+			idx, chan, ret);
+	}
+
 	/* SCPI error codes > 0, translate them to Linux scale*/
 	return ret > 0 ? scpi_to_linux_errno(ret) : ret;
 }
@@ -979,6 +985,8 @@
 		struct mbox_client *cl = &pchan->cl;
 		struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 
+		_dev_info(dev, "get channel%d", idx);
+
 		ret = of_address_to_resource(shmem, 0, &res);
 		of_node_put(shmem);
 		if (ret) {