[PATCH AUTOSEL 5.4 136/330] dmaengine: stm32-mdma: use vchan_terminate_vdesc() in .terminate_all

Sasha Levin
2020-09-18T02:04:11Z

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

[ Upstream commit dfc708812a2acfc0ca56f56233b3c3e7b0d4ffe7 ]

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

Move vdesc->node list_del in stm32_mdma_start_transfer instead of in
stm32_mdma_xfer_end 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/20200127085334.13163-7-amelie.delaunay@st.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/stm32-mdma.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index 5838311cf9900..ee1cbf3be75d5 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1127,6 +1127,8 @@ static void stm32_mdma_start_transfer(struct stm32_mdma_chan *chan)
return;
}

+ list_del(&vdesc->node);
+
chan->desc = to_stm32_mdma_desc(vdesc);
hwdesc = chan->desc->node[0].hwdesc;
chan->curr_hwdesc = 0;
@@ -1242,8 +1244,10 @@ static int stm32_mdma_terminate_all(struct dma_chan *c)
LIST_HEAD(head);

spin_lock_irqsave(&chan->vchan.lock, flags);
- if (chan->busy) {
- stm32_mdma_stop(chan);
+ if (chan->desc) {
+ vchan_terminate_vdesc(&chan->desc->vdesc);
+ if (chan->busy)
+ stm32_mdma_stop(chan);
chan->desc = NULL;
}
vchan_get_all_descriptors(&chan->vchan, &head);
@@ -1331,7 +1335,6 @@ static enum dma_status stm32_mdma_tx_status(struct dma_chan *c,

static void stm32_mdma_xfer_end(struct stm32_mdma_chan *chan)
{
- list_del(&chan->desc->vdesc.node);
vchan_cookie_complete(&chan->desc->vdesc);
chan->desc = NULL;
chan->busy = false;
--
2.25.1