diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 66eb3f0e5dafc..5e8e9337adc71 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -335,6 +335,10 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
 		return;
 	}
 
+	/* rx.len could be shrunk in the sync do_xfer, so reset to maxsz */
+	if (msg_type == MSG_TYPE_DELAYED_RESP)
+		xfer->rx.len = info->desc->max_msg_size;
+
 	scmi_dump_header_dbg(dev, &xfer->hdr);
 
 	info->desc->ops->fetch_response(cinfo, xfer);