dmaengine: Clarify device parameter for dma_sync_*_for_*()

Signed-off-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Vinod Koul <[email protected]>
This commit is contained in:
Geert Uytterhoeven 2014-07-11 17:56:21 +02:00 • committed by Vinod Koul
commit 70c9b8bd7a

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@ -100,8 +100,10 @@ The slave DMA usage consists of following steps:
The peripheral driver is expected to have mapped the scatterlist for
the DMA operation prior to calling device_prep_slave_sg, and must
keep the scatterlist mapped until the DMA operation has completed.
The scatterlist must be mapped using the DMA struct device. So,
normal setup should look like this:
The scatterlist must be mapped using the DMA struct device.
If a mapping needs to be synchronized later, dma_sync_*_for_*() must be
called using the DMA struct device, too.
So, normal setup should look like this:
nr_sg = dma_map_sg(chan->device->dev, sgl, sg_len);
if (nr_sg == 0)