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With a plain spin_lock(), the desc_task tasklet can > run on the same CPU while the lock is held, and spin on it forever. > > Reported-by: Sashiko > Link: https://lore.kernel.org/dmaengine/20260717223217.B6FBF1F000E9@smtp.kernel.org > Signed-off-by: Logan Gunthorpe > --- Reviewed-by: Frank Li > drivers/dma/plx_dma.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma/plx_dma.c b/drivers/dma/plx_dma.c > index e4243b66f933..8c4b19d681ad 100644 > --- a/drivers/dma/plx_dma.c > +++ b/drivers/dma/plx_dma.c > @@ -138,7 +138,7 @@ static void plx_dma_process_desc(struct plx_dma_dev *plxdev) > struct plx_dma_desc *desc; > u32 flags; > > - spin_lock(&plxdev->ring_lock); > + spin_lock_bh(&plxdev->ring_lock); > > while (plxdev->tail != plxdev->head) { > desc = plx_dma_get_desc(plxdev, plxdev->tail); > @@ -172,7 +172,7 @@ static void plx_dma_process_desc(struct plx_dma_dev *plxdev) > plxdev->tail++; > } > > - spin_unlock(&plxdev->ring_lock); > + spin_unlock_bh(&plxdev->ring_lock); > } > > static void plx_dma_abort_desc(struct plx_dma_dev *plxdev) > -- > 2.47.3 >