[alsa-devel] async between dmaengine_pcm_dma_complete and snd_pcm_release

Vinod Koul vinod.koul at intel.com
Thu Oct 10 04:56:25 CEST 2013

On Thu, Oct 10, 2013 at 09:05:02AM +0800, Qiao Zhou wrote:
> On 10/09/2013 07:00 PM, Lars-Peter Clausen wrote:
> >I think we'll eventually need to versions of dmaengine_terminate_all(). A
> >sync version which makes sure that the tasklet has finished and a non-sync
> >version that only makes sure that no new callbacks are started. I think the
> >sync version should be the default with an optional async version which must
> >be used, if it can run from within the callback. So we'd call the async
> >version in the pcm_trigger callback and the sync version in the pcm_close
> >callback.
> In our current dmaengine driver, the dma interrupt is disabled in
> terminate_all, so there is no new callback after it. This is the
> async version. Takashi also mentions the requirement for such sync
> version. I'll investigate the sync version more. thanks a lot.
Your issue seems to be more on the case callback has been onvoked while the
terminate_all in processing and after that case when sound core freed the
pointers. If you get a new callback after the terminate_all then taht would only
be a driver bug!


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