dmaengine: rcar-dmac: implement device_synchronize()

Implement the device_synchronize() callback which wait until a dma
channel is stopped to provide a synchronization point.

This protects the driver from multiple race conditions when terminating
and freeing resources. E.g. the completion callback still running after
device_terminate_all() has completed.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Niklas Söderlund 2017-05-16 01:09:16 +02:00 committed by Vinod Koul
parent 427d5ecd27
commit 30c45005a4
1 changed files with 8 additions and 0 deletions

View File

@ -1365,6 +1365,13 @@ done:
spin_unlock_irqrestore(&rchan->lock, flags);
}
static void rcar_dmac_device_synchronize(struct dma_chan *chan)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
synchronize_irq(rchan->irq);
}
/* -----------------------------------------------------------------------------
* IRQ handling
*/
@ -1846,6 +1853,7 @@ static int rcar_dmac_probe(struct platform_device *pdev)
engine->device_terminate_all = rcar_dmac_chan_terminate_all;
engine->device_tx_status = rcar_dmac_tx_status;
engine->device_issue_pending = rcar_dmac_issue_pending;
engine->device_synchronize = rcar_dmac_device_synchronize;
ret = dma_async_device_register(engine);
if (ret < 0)