dmaengine: at_hdmac: fix race condition in atc_advance_work()
The BUG_ON() directive is triggered probably due to a latency
modification following inclusion of commit c10d73671a
("softirq:
reduce latencies"). This condition has not been met before 3.9-rc1 and
doesn't trigger without this patch.
We now make sure that DMA channel is idle before calling
atc_complete_all() which makes the BUG_ON() "protection" useless.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
ebe8054433
commit
d202f05158
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@ -310,8 +310,6 @@ static void atc_complete_all(struct at_dma_chan *atchan)
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dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
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BUG_ON(atc_chan_is_enabled(atchan));
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/*
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* Submit queued descriptors ASAP, i.e. before we go through
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* the completed ones.
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@ -368,6 +366,9 @@ static void atc_advance_work(struct at_dma_chan *atchan)
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{
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dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
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if (atc_chan_is_enabled(atchan))
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return;
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if (list_empty(&atchan->active_list) ||
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list_is_singular(&atchan->active_list)) {
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atc_complete_all(atchan);
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@ -1078,9 +1079,7 @@ static void atc_issue_pending(struct dma_chan *chan)
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return;
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spin_lock_irqsave(&atchan->lock, flags);
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if (!atc_chan_is_enabled(atchan)) {
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atc_advance_work(atchan);
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}
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atc_advance_work(atchan);
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spin_unlock_irqrestore(&atchan->lock, flags);
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}
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