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[v2,2/6] dmaengine: sprd: Add validation of current descriptor in irq handler

Message ID 6eee7d5ad68d60ebedf443e24678e5b467fcf0e6.1557127239.git.baolin.wang@linaro.org
State New
Headers show
Series Fix some bugs and add new feature for Spreadtrum DMA engine | expand

Commit Message

(Exiting) Baolin Wang May 6, 2019, 7:28 a.m. UTC
When user terminates one DMA channel to free all its descriptors, but
at the same time one transaction interrupt was triggered possibly, now
we should not handle this interrupt by validating if the 'schan->cur_desc'
was set as NULL to avoid crashing the kernel.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

---
 drivers/dma/sprd-dma.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

-- 
1.7.9.5
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Patch

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index e29342a..431e289 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -552,12 +552,17 @@  static irqreturn_t dma_irq_handle(int irq, void *dev_id)
 		schan = &sdev->channels[i];
 
 		spin_lock(&schan->vc.lock);
+
+		sdesc = schan->cur_desc;
+		if (!sdesc) {
+			spin_unlock(&schan->vc.lock);
+			return IRQ_HANDLED;
+		}
+
 		int_type = sprd_dma_get_int_type(schan);
 		req_type = sprd_dma_get_req_type(schan);
 		sprd_dma_clear_int(schan);
 
-		sdesc = schan->cur_desc;
-
 		/* cyclic mode schedule callback */
 		cyclic = schan->linklist.phy_addr ? true : false;
 		if (cyclic == true) {