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Re: [PATCH v2] dmaengine: edma: Implement device_synchronize callback

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On 02/11/2016 10:08 AM, Peter Ujfalusi wrote:
> We need the callback to support the dmaengine_terminate_sync().
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>

Looks good, but I noticed a slight race condition in
edma_completion_handler(). You need to fetch echan->desc while holding the
vchan.lock. Otherwise this can race against terminate_all() and the callback
might get scheduled even though terminate_all() completed and then there is
a race where the synchronize() operation could be called before the callback
gets scheduled, which means it doesn't do its intended job. Highly unlikely
to happen, but theoretically possible.

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[PATCH v2] dmaengine: edma: Implement device_synchronize callback Peter Ujfalusi <peter.ujfalusi@ti.com> - 2016-02-11 10:20 +0100
  Re: [PATCH v2] dmaengine: edma: Implement device_synchronize callback Lars-Peter Clausen <lars@metafoo.de> - 2016-02-11 10:50 +0100
    Re: [PATCH v2] dmaengine: edma: Implement device_synchronize callback Peter Ujfalusi <peter.ujfalusi@ti.com> - 2016-02-11 12:20 +0100
      Re: [PATCH v2] dmaengine: edma: Implement device_synchronize callback Lars-Peter Clausen <lars@metafoo.de> - 2016-02-11 13:40 +0100
  Re: [PATCH v2] dmaengine: edma: Implement device_synchronize callback Vinod Koul <vinod.koul@intel.com> - 2016-02-22 03:50 +0100

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