[PATCH v2] dmaengine: edma: Implement device_synchronize callback
From: lars@metafoo.de (Lars-Peter Clausen)
Date: 2016-02-11 09:46:42
Also in:
linux-omap, lkml
From: lars@metafoo.de (Lars-Peter Clausen)
Date: 2016-02-11 09:46:42
Also in:
linux-omap, lkml
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 <redacted>
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.