2013-06-07 11:42:49

by Qiao Zhou

Subject: [PATCH] dma: mmp_tdma: kill tasklet when free dma channel

kill tasklet task when free dam channel, otherwise the task may
run after related resource is released, then unknown things may
happen.

Signed-off-by: Qiao Zhou <[email protected]>
---
drivers/dma/mmp_tdma.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/mmp_tdma.c b/drivers/dma/mmp_tdma.c
index 43d5a6c..2622b2a 100644
--- a/drivers/dma/mmp_tdma.c
+++ b/drivers/dma/mmp_tdma.c
@@ -333,6 +333,9 @@ static void mmp_tdma_free_chan_resources(struct dma_chan *chan)

if (tdmac->irq)
devm_free_irq(tdmac->dev, tdmac->irq, tdmac);
+
+ tasklet_kill(&tdmac->tasklet);
+
mmp_tdma_free_descriptor(tdmac);
return;
}
--
1.7.0.4

2013-06-12 10:31:17

by Vinod Koul

Subject: Re: [PATCH] dma: mmp_tdma: kill tasklet when free dma channel

On Fri, Jun 07, 2013 at 07:40:40PM +0800, Qiao Zhou wrote:
> kill tasklet task when free dam channel, otherwise the task may
typo ^^^^

> run after related resource is released, then unknown things may
> happen.
Well, why would tasklet run when channel is freed. You are supposed to cleanup
the DMA channel on free. Ensure all transaction are aborted

Sounds like masking some issue

--
~Vinod
>
> Signed-off-by: Qiao Zhou <[email protected]>
> ---
> drivers/dma/mmp_tdma.c | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/dma/mmp_tdma.c b/drivers/dma/mmp_tdma.c
> index 43d5a6c..2622b2a 100644
> --- a/drivers/dma/mmp_tdma.c
> +++ b/drivers/dma/mmp_tdma.c
> @@ -333,6 +333,9 @@ static void mmp_tdma_free_chan_resources(struct dma_chan *chan)
>
> if (tdmac->irq)
> devm_free_irq(tdmac->dev, tdmac->irq, tdmac);
> +
> + tasklet_kill(&tdmac->tasklet);
> +
> mmp_tdma_free_descriptor(tdmac);
> return;
> }
> --
> 1.7.0.4
>

--