1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 8654049a70c0..6153a42d68db 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -501,7 +501,11 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
                 memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
         else {
                 size_t first = UART_XMIT_SIZE - xmit->tail;
-                size_t second = xmit->head;
+                size_t second;
+
+                if (first > count)
+                        first = count;
+                second = count - first;
 
                 memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
                 if (second)