From 70c9b8bd7ac4931c775dab77ad29117523bf0956 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Fri, 11 Jul 2014 17:56:21 +0200
Subject: dmaengine: Clarify device parameter for dma_sync_*_for_*()
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---
Documentation/dmaengine.txt | 6 ++++--
1 file 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)
--
cgit