From mboxrd@z Thu Jan 1 00:00:00 1970 From: 21cnbao@gmail.com (Barry Song) Date: Tue, 14 Jul 2015 00:28:25 +0000 Subject: [PATCH] dmaengine: sirf: fix kernel panic under one race condition Message-ID: <1436833705-6550-1-git-send-email-21cnbao@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Yanchang Li 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 Signed-off-by: Barry Song --- 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