Commit 2ed08629 authored Oct 20, 2015 by Lars-Peter Clausen Committed by Vinod Koul Nov 16, 2015

dmaengine: virt-dma: Add synchronization helper function



Add a synchronize helper function for the virt-dma library. The function
makes sure that any scheduled descriptor complete callbacks have finished
running before the function returns.

This needs to be called by drivers using virt-dma in their
device_synchronize() callback. Depending on the driver additional
operations might be necessary in addition to calling vchan_synchronize() to
ensure proper synchronization.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

parent b36f09c3

drivers/dma/virt-dma.h

+13 −0

Original line number	Diff line number	Diff line
		@@ -151,4 +151,17 @@ static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
		vchan_dma_desc_free_list(vc, &head);
		}

		/**
		* vchan_synchronize() - synchronize callback execution to the current context
		* @vc: virtual channel to synchronize
		*
		* Makes sure that all scheduled or active callbacks have finished running. For
		* proper operation the caller has to ensure that no new callbacks are scheduled
		* after the invocation of this function started.
		*/
		static inline void vchan_synchronize(struct virt_dma_chan *vc)
		{
		tasklet_kill(&vc->task);
		}

		#endif