The commit af19b7ce76ba ("mmc: bcm2835: Avoid possible races on
data requests") introduces a possible circular locking dependency,
which is triggered by swapping to the sdhost interface.
So instead of reintroduce the race condition again, we could also
avoid this situation by using GFP_NOWAIT for the allocation of the
DMA buffer descriptors.
Reported-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Fixes: af19b7ce76ba ("mmc: bcm2835: Avoid possible races on data requests")
Link: http://lists.infradead.org/pipermail/linux-rpi-kernel/2019-March/008615.html
---
drivers/dma/bcm2835-dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index ec8a291..54093ff 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -671,7 +671,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
d = bcm2835_dma_create_cb_chain(chan, direction, false,
info, extra,
frames, src, dst, 0, 0,
- GFP_KERNEL);
+ GFP_NOWAIT);
if (!d)
return NULL;
--
2.7.4
