From: Andrew Jackson <Andrew.Jackson@arm.com>
To: Russell King <linux@arm.linux.org.uk>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.cz>,
linux-serial@vger.kernel.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: [PATCH 2/5] serial: pl011: Avoid assumptions about buffer size when refilling TX DMA
Date: Fri, 07 Nov 2014 14:14:39 +0000 [thread overview]
Message-ID: <545CD3CF.4070901@arm.com> (raw)
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>
---
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
WARNING: multiple messages have this Message-ID (diff)
From: Andrew.Jackson@arm.com (Andrew Jackson)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/5] serial: pl011: Avoid assumptions about buffer size when refilling TX DMA
Date: Fri, 07 Nov 2014 14:14:39 +0000 [thread overview]
Message-ID: <545CD3CF.4070901@arm.com> (raw)
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>
---
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
next reply other threads:[~2014-11-07 14:14 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-07 14:14 Andrew Jackson [this message]
2014-11-07 14:14 ` [PATCH 2/5] serial: pl011: Avoid assumptions about buffer size when refilling TX DMA Andrew Jackson
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