[PATCH] dmaengine: sun6i: Fix potential deadlock in sun6i_dma_terminate_all()

[Hongling Zeng]

sun6i_dma_terminate_all() acquires sdev->lock with plain spin_lock()
from process context. Since interrupts remain enabled, a DMA interrupt
can fire on the same CPU while the lock is held. The interrupt handler
schedules sun6i_dma_tasklet(), which attempts to acquire the same lock
with spin_lock_irq(), causing a deadlock.

Fix by using spin_lock_irq() to disable interrupts while holding
sdev->lock, consistent with other call sites.

Fixes: ba489fd46ab6 ("dmaengine: sun6i: Add support for Allwinner A31 DMA controller")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Hongling Zeng <zenghongling@xxxxxxxxxx>
---
 drivers/dma/sun6i-dma.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index a9a254dbf8cb..840f7276ad5d 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -939,9 +939,9 @@ static int sun6i_dma_terminate_all(struct dma_chan *chan)
 	unsigned long flags;
 	LIST_HEAD(head);
 
-	spin_lock(&sdev->lock);
+	spin_lock_irq(&sdev->lock);
 	list_del_init(&vchan->node);
-	spin_unlock(&sdev->lock);
+	spin_unlock_irq(&sdev->lock);
 
 	spin_lock_irqsave(&vchan->vc.lock, flags);
 
-- 
2.25.1