[PATCH AUTOSEL 5.4 140/330] dmaengine: stm32-dma: use vchan_terminate_vdesc() in .terminate_all

Sasha Levin
2020-09-18T03:06:38Z

From: Amelie Delaunay <amelie.delaunay@st.com>

[ Upstream commit d80cbef35bf89b763f06e03bb4ff8f933bf012c5 ]

To avoid race with vchan_complete, use the race free way to terminate
running transfer.

Move vdesc->node list_del in stm32_dma_start_transfer instead of in
stm32_mdma_chan_complete to avoid another race in vchan_dma_desc_free_list.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-9-amelie.delaunay@st.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/stm32-dma.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 5989b08935211..6c5771de32c67 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -488,8 +488,10 @@ static int stm32_dma_terminate_all(struct dma_chan *c)

spin_lock_irqsave(&chan->vchan.lock, flags);

- if (chan->busy) {
- stm32_dma_stop(chan);
+ if (chan->desc) {
+ vchan_terminate_vdesc(&chan->desc->vdesc);
+ if (chan->busy)
+ stm32_dma_stop(chan);
chan->desc = NULL;
}

@@ -545,6 +547,8 @@ static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
if (!vdesc)
return;

+ list_del(&vdesc->node);
+
chan->desc = to_stm32_dma_desc(vdesc);
chan->next_sg = 0;
}
@@ -622,7 +626,6 @@ static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
} else {
chan->busy = false;
if (chan->next_sg == chan->desc->num_sgs) {
- list_del(&chan->desc->vdesc.node);
vchan_cookie_complete(&chan->desc->vdesc);
chan->desc = NULL;
}
--
2.25.1