[PATCH 6/6] dmaengine: at_hdmac: fix race while monitoring channel status
Nicolas Ferre
nicolas.ferre at atmel.com
Wed Jan 12 09:39:10 EST 2011
We were reading channel status then taking a lock. This lead to a race because
this lock may delay us and then make this channel not idle anymore.
Signed-off-by: Nicolas Ferre <nicolas.ferre at atmel.com>
---
drivers/dma/at_hdmac.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 99942a5..3d7d705 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -853,11 +853,11 @@ static void atc_issue_pending(struct dma_chan *chan)
dev_vdbg(chan2dev(chan), "issue_pending\n");
+ spin_lock_bh(&atchan->lock);
if (!atc_chan_is_enabled(atchan)) {
- spin_lock_bh(&atchan->lock);
atc_advance_work(atchan);
- spin_unlock_bh(&atchan->lock);
}
+ spin_unlock_bh(&atchan->lock);
}
/**
--
1.7.3
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