diff options
Diffstat (limited to 'Documentation/dmaengine.txt')
| -rw-r--r-- | Documentation/dmaengine.txt | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/Documentation/dmaengine.txt b/Documentation/dmaengine.txt index 2def665baf6e..573e28ce9751 100644 --- a/Documentation/dmaengine.txt +++ b/Documentation/dmaengine.txt @@ -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) |