dmaengine: stm32-mdma: use vchan_terminate_vdesc() in .terminate_all

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>

diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index f2043f4..5469563 100644 (file)
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1126,6 +1126,8 @@ 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;
@@ -1241,8 +1243,10 @@ 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);
@@ -1330,7 +1334,6 @@ 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;