From: Qiao Zhou Date: Wed, 4 Feb 2015 06:16:03 +0000 (+0800) Subject: dmaenegine: mmp-pdma: fix irq handler overwrite physical chan issue X-Git-Tag: firefly_0821_release~176^2~2196^2~8 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3a314f143d82603bd697d7eb6c76518afc3595bc;p=firefly-linux-kernel-4.4.55.git 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 --- diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index 8926f271904e..abf1450bb25d 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);