From: Viresh Kumar <viresh.kumar@st.com>
Date: Thu, 3 Mar 2011 10:17:17 +0000 (+0530)
Subject: dw_dmac: Calling dwc_scan_descriptors from dwc_tx_status() after taking lock
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=569432efa7975f5795efb8142134f5a098942381;p=mv-sheeva.git

dw_dmac: Calling dwc_scan_descriptors from dwc_tx_status() after taking lock

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@st.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 942b50f57f2..2b0d5e99ae7 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;