From e2a545a6aee935e44db08797f7155be38f3c18f9 Mon Sep 17 00:00:00 2001 From: Andrew Jackson Date: Fri, 7 Nov 2014 14:14:39 +0000 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/amba-pl011.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) 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) -- 2.39.5