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authorAndrew Jackson <Andrew.Jackson@arm.com>2014-11-07 15:14:39 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-07 17:35:55 +0100
commite2a545a6aee935e44db08797f7155be38f3c18f9 (patch)
treeac6c5ec14ec191afcd2bbb5fea391c8c4976aee3
parentserial: pl011: Allocate TX DMA buffer from DMA capable memory (diff)
downloadlinux-e2a545a6aee935e44db08797f7155be38f3c18f9.tar.xz
linux-e2a545a6aee935e44db08797f7155be38f3c18f9.zip
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>
-rw-r--r--drivers/tty/serial/amba-pl011.c6
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)