From: Baolin Wang baolin.wang@linaro.org
[ Upstream commit 58152b0e573e5581c4b9ef7cf06d2e9fafae27d4 ]
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 Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/sprd-dma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c index e29342ab85f6..431e289d59a5 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) {