[PATCH 6/7] dmaengine: mxs-dma: synchronize tasklet when freeing a channel

[Jiale Yao <yaojiale02@163.com>]

The DMA interrupt handler schedules a per-channel tasklet to invoke the
completion callback. Releasing the IRQ does not drain a tasklet that was
already queued, so the callback can run after its client state has been
released.

Kill the tasklet after freeing the IRQ and before releasing the channel
command storage and clock.

Fixes: a580b8c5429a ("dmaengine: mxs-dma: add dma support for i.MX23/28")
Signed-off-by: Jiale Yao <yaojiale02@163.com>
---
 drivers/dma/mxs-dma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index 7acb3d29dad3..9e85ba45f0fa 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -442,6 +442,7 @@ static void mxs_dma_free_chan_resources(struct dma_chan *chan)
 	mxs_dma_disable_chan(chan);
 
 	free_irq(mxs_chan->chan_irq, mxs_dma);
+	tasklet_kill(&mxs_chan->tasklet);
 
 	dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
 			mxs_chan->ccw, mxs_chan->ccw_phys);
-- 
2.34.1