serial: pl011: Avoid assumptions about buffer size when refilling TX DMA
The existing code assumed that PL011_DMA_BUFFER_SIZE == UART_XMIT_SIZE,
which may not always be the case. This allows for these two being
different sizes and not copying too much data.
Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 8654049..6153a42 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -501,7 +501,11 @@
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)