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Subject[PATCH v2 1/2] dmaengine: Clarify device parameter for dma_sync_*_for_*()
Date
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v2:
- New
---
Documentation/dmaengine.txt | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Documentation/dmaengine.txt b/Documentation/dmaengine.txt
index 879b6e31e2da..87d3f192e160 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)
--
1.9.1


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