From: Amelie Delaunay <amelie.delau...@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.delau...@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-9-amelie.delau...@st.com
Signed-off-by: Vinod Koul <vk...@kernel.org>
Signed-off-by: Sasha Levin <sas...@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 4903a408fc146..ac7af440f8658 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -494,8 +494,10 @@ 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;
        }
 
@@ -551,6 +553,8 @@ 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;
        }
@@ -628,7 +632,6 @@ 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

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