[PATCH] dmaengine: sirf: fix kernel panic under one race condition

[Barry Song]

From: Yanchang Li <yl22 at csr.com>

If DMA interrupt comes and is latched by IRQ controller during the
execution of dma_terminate_all(), dma_irq routine will be executed
after dma terminated, and it will cause kernel panic.
We clear DMA interrupts in dma_terminate_all() to avoid this useless
interrupt.

Signed-off-by: Yanchang Li <yl22 at csr.com>
Signed-off-by: Barry Song <Baohua.Song at csr.com>
---
 drivers/dma/sirf-dma.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/dma/sirf-dma.c b/drivers/dma/sirf-dma.c
index 8c5186c..7d5598d 100644
--- a/drivers/dma/sirf-dma.c
+++ b/drivers/dma/sirf-dma.c
@@ -455,6 +455,7 @@ static int sirfsoc_dma_terminate_all(struct dma_chan *chan)
 	switch (sdma->type) {
 	case SIRFSOC_DMA_VER_A7V1:
 		writel_relaxed(1 << cid, sdma->base + SIRFSOC_DMA_INT_EN_CLR);
+		writel_relaxed(1 << cid, sdma->base + SIRFSOC_DMA_CH_INT);
 		writel_relaxed((1 << cid) | 1 << (cid + 16),
 			       sdma->base +
 			       SIRFSOC_DMA_CH_LOOP_CTRL_CLR_ATLAS7);
@@ -462,6 +463,8 @@ static int sirfsoc_dma_terminate_all(struct dma_chan *chan)
 		break;
 	case SIRFSOC_DMA_VER_A7V2:
 		writel_relaxed(0, sdma->base + SIRFSOC_DMA_INT_EN_ATLAS7);
+		writel_relaxed(SIRFSOC_DMA_INT_ALL_ATLAS7,
+			       sdma->base + SIRFSOC_DMA_INT_ATLAS7);
 		writel_relaxed(0, sdma->base + SIRFSOC_DMA_LOOP_CTRL_ATLAS7);
 		writel_relaxed(0, sdma->base + SIRFSOC_DMA_VALID_ATLAS7);
 		break;
-- 
2.3.5