From 6758ddafad55fc8e665bb03ff103d3e410483fe9 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Fri, 1 Aug 2014 18:51:46 +0200 Subject: dma: at_hdmac: fix invalid remaining bytes detection 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 Signed-off-by: Vinod Koul --- 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 d20ab1b..ca9dd26 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 -- cgit v1.1