[PATCH V2 04/13] dw_dmac: Calling dwc_scan_descriptors from dwc_tx_status() after taking lock

From: Viresh Kumar
Date: Thu Mar 03 2011 - 05:18:34 EST


Lock must be taken before calling dwc_scan_descriptors, as this may
access/modify shared data and queues. dwc_tx_status wasn't taking lock before
calling this routine. This patch add code that takes lock before calling
dwc_scan_descriptors.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxx>
---
drivers/dma/dw_dmac.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 942b50f..2b0d5e9 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -836,7 +836,9 @@ dwc_tx_status(struct dma_chan *chan,

ret = dma_async_is_complete(cookie, last_complete, last_used);
if (ret != DMA_SUCCESS) {
+ spin_lock_bh(&dwc->lock);
dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
+ spin_unlock_bh(&dwc->lock);

last_complete = dwc->completed;
last_used = chan->cookie;
--
1.7.2.2

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