[PATCH 2/5] serial: pl011: Avoid assumptions about buffer size when refilling TX DMA
From: Andrew Jackson <hidden>
Date: 2014-11-07 14:16:24
Also in:
linux-serial, lkml
Subsystem:
arm primecell uart pl010 and pl011 drivers, the rest, tty layer and serial drivers · Maintainers:
Russell King, Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
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 <redacted> --- drivers/tty/serial/amba-pl011.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index a285196..d8d067a 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)
--
1.7.1