[PATCH 7/7] dmaengine: ste_dma40: synchronize tasklet when releasing a channel

[Jiale Yao]

DMA completion handling schedules a per-channel tasklet that processes
completed descriptors and invokes client callbacks. Channel release
terminates and frees the descriptor state without draining a tasklet
that was already queued.

After d40_free_dma() removes the channel from the interrupt lookup
tables, kill the tasklet before returning the channel to the DMAengine
core.

Fixes: 8d318a50b3d7 ("DMAENGINE: Support for ST-Ericssons DMA40 block v3")
Signed-off-by: Jiale Yao <yaojiale02 at 163.com>
---
 drivers/dma/ste_dma40.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 0d9ffa3e2663..647a265590c2 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -2484,6 +2484,8 @@ static void d40_free_chan_resources(struct dma_chan *chan)
 	if (err)
 		chan_err(d40c, "Failed to free channel\n");
 	spin_unlock_irqrestore(&d40c->lock, flags);
+
+	tasklet_kill(&d40c->tasklet);
 }
 
 static struct dma_async_tx_descriptor *d40_prep_memcpy(struct dma_chan *chan,
-- 
2.34.1