[PATCH 1/3] dmaengine: stm32-mdma: abort resume if no ongoing transfer
Amelie Delaunay
amelie.delaunay at foss.st.com
Wed Oct 4 09:35:28 PDT 2023
chan->desc can be null, if transfer is terminated when resume is called,
leading to a NULL pointer when retrieving the hwdesc.
To avoid this case, check that chan->desc is not null and channel is
disabled (transfer previously paused or terminated).
Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver")
Signed-off-by: Amelie Delaunay <amelie.delaunay at foss.st.com>
Cc: stable at vger.kernel.org
---
drivers/dma/stm32-mdma.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index 0de234022c6d..cc6f4b00091f 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1236,6 +1236,10 @@ static int stm32_mdma_resume(struct dma_chan *c)
unsigned long flags;
u32 status, reg;
+ /* Transfer can be terminated */
+ if (!chan->desc || (stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & STM32_MDMA_CCR_EN))
+ return -EPERM;
+
hwdesc = chan->desc->node[chan->curr_hwdesc].hwdesc;
spin_lock_irqsave(&chan->vchan.lock, flags);
--
2.25.1
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