* [PATCH] dma: at_hdmac: fix invalid remaining bytes detection
@ 2014-08-01 10:03 Alexandre Belloni
2014-08-01 14:08 ` Sergei Shtylyov
0 siblings, 1 reply; 2+ messages in thread
From: Alexandre Belloni @ 2014-08-01 10:03 UTC (permalink / raw)
To: Nicolas Ferre
Cc: Ludovic Desroches, linux-arm-kernel, linux-kernel, dmaengine,
Alexandre Belloni
Found using smatch:
drivers/dma/at_hdmac.c:299 atc_get_bytes_left() warn: unsigned
'atchan->remain_desc' is never less than zero.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
drivers/dma/at_hdmac.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index c13a3bb0f594..9ec84ee2fa25 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -294,14 +294,16 @@ static int atc_get_bytes_left(struct dma_chan *chan)
ret = -EINVAL;
goto out;
}
- atchan->remain_desc -= (desc_cur->lli.ctrla & ATC_BTSIZE_MAX)
- << (desc_first->tx_width);
- if (atchan->remain_desc < 0) {
+
+ count = (desc_cur->lli.ctrla & ATC_BTSIZE_MAX)
+ << (desc_first->tx_width);
+ if (atchan->remain_desc < count) {
ret = -EINVAL;
goto out;
- } else {
- ret = atchan->remain_desc;
}
+
+ atchan->remain_desc -= count;
+ ret = atchan->remain_desc;
} else {
/*
* Get residual bytes when current
--
1.9.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] dma: at_hdmac: fix invalid remaining bytes detection
2014-08-01 10:03 [PATCH] dma: at_hdmac: fix invalid remaining bytes detection Alexandre Belloni
@ 2014-08-01 14:08 ` Sergei Shtylyov
0 siblings, 0 replies; 2+ messages in thread
From: Sergei Shtylyov @ 2014-08-01 14:08 UTC (permalink / raw)
To: Alexandre Belloni, Nicolas Ferre
Cc: dmaengine, Ludovic Desroches, linux-kernel, linux-arm-kernel
Hello.
On 08/01/2014 02:03 PM, Alexandre Belloni wrote:
> Found using smatch:
> drivers/dma/at_hdmac.c:299 atc_get_bytes_left() warn: unsigned
> 'atchan->remain_desc' is never less than zero.
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> drivers/dma/at_hdmac.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index c13a3bb0f594..9ec84ee2fa25 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -294,14 +294,16 @@ static int atc_get_bytes_left(struct dma_chan *chan)
> ret = -EINVAL;
> goto out;
> }
> - atchan->remain_desc -= (desc_cur->lli.ctrla & ATC_BTSIZE_MAX)
> - << (desc_first->tx_width);
> - if (atchan->remain_desc < 0) {
> +
> + count = (desc_cur->lli.ctrla & ATC_BTSIZE_MAX)
> + << (desc_first->tx_width);
Parens not needed here.
[...]
WBR, Sergei
^ permalink raw reply [flat|nested] 2+ messages in thread
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2014-08-01 14:08 ` Sergei Shtylyov
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