From 3a314f143d82603bd697d7eb6c76518afc3595bc Mon Sep 17 00:00:00 2001 From: Qiao Zhou Date: Wed, 4 Feb 2015 14:16:03 +0800 Subject: [PATCH] dmaenegine: mmp-pdma: fix irq handler overwrite physical chan issue Some dma channels may be reserved for other purpose in other layer, like secure driver in EL2/EL3. PDMA driver can see the interrupt status, but it should not try to handle related interrupt, since it doesn't belong to PDMA driver in kernel. These interrupts should be handled by corresponding client/module.Otherwise, it will overwrite illegal memory and cause unexpected issues, since pdma driver only requests resources for pdma channels. In PDMA driver, the reserved channels are at the end of total 32 channels. If we find interrupt bit index is not smaller than total dma channels, we should ignore it. Signed-off-by: Qiao Zhou Acked-by: Zhangfei Gao Signed-off-by: Vinod Koul --- drivers/dma/mmp_pdma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index 8926f27..abf1450 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -219,6 +219,9 @@ static irqreturn_t mmp_pdma_int_handler(int irq, void *dev_id) while (dint) { i = __ffs(dint); + /* only handle interrupts belonging to pdma driver*/ + if (i >= pdev->dma_channels) + break; dint &= (dint - 1); phy = &pdev->phy[i]; ret = mmp_pdma_chan_handler(irq, phy); -- 2.7.4