[PATCH 4/7] dmaengine: mmp_tdma: synchronize tasklet when freeing a channel

[Jiale Yao]

The channel interrupt handler schedules a tasklet to invoke the transfer
completion callback. Channel resource release does not drain a tasklet
that was already queued, so a callback can run after its client state has
been released.

Disable the channel to stop the shared interrupt path from producing
more completions, release a dedicated IRQ when present, and kill the
tasklet before freeing the descriptor storage.

Fixes: c6da0ba8dfc8 ("dmaengine: mmp_tdma: add mmp tdma support")
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/dma/mmp_tdma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/mmp_tdma.c b/drivers/dma/mmp_tdma.c
index ba03321eeff7..e0de0967d7e7 100644
--- a/drivers/dma/mmp_tdma.c
+++ b/drivers/dma/mmp_tdma.c
@@ -399,8 +399,10 @@ static void mmp_tdma_free_chan_resources(struct dma_chan *chan)
 {
 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
 
+	mmp_tdma_disable_chan(chan);
 	if (tdmac->irq)
 		devm_free_irq(tdmac->dev, tdmac->irq, tdmac);
+	tasklet_kill(&tdmac->tasklet);
 	mmp_tdma_free_descriptor(tdmac);
 	return;
 }
-- 
2.34.1