From: Sakari Ailus <sakari.ailus@xxxxxx>
The nents argument to the DMA API functions operating on scatterlists is
always the same. The documentation used different argument names and the
matter was not mentioned in Documentation/DMA-API-HOWTO.txt at all. Fix
these.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
Documentation/DMA-API-HOWTO.txt | 5 +++++
Documentation/DMA-API.txt | 6 +++---
2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt
index 55b70b9..d69b3fc 100644
--- a/Documentation/DMA-API-HOWTO.txt
+++ b/Documentation/DMA-API-HOWTO.txt
@@ -681,6 +681,11 @@ or:
as appropriate.
+PLEASE NOTE: The 'nents' argument to dma_sync_sg_for_cpu() and
+ dma_sync_sg_for_device() must be the same passed to
+ dma_map_sg(). It is _NOT_ the count returned by
+ dma_map_sg().
+
After the last DMA transfer call one of the DMA unmap routines
dma_unmap_{single,sg}(). If you don't touch the data from the first
dma_map_*() call till dma_unmap_*(), then you don't have to call the
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index edccacd..8d065d6 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -340,7 +340,7 @@ accessed sg->address and sg->length as shown above.
void
dma_unmap_sg(struct device *dev, struct scatterlist *sg,
- int nhwentries, enum dma_data_direction direction)
+ int nents, enum dma_data_direction direction)
Unmap the previously mapped scatter/gather list. All the parameters
must be the same as those and passed in to the scatter/gather mapping
@@ -356,10 +356,10 @@ void
dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
void
-dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
+dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction direction)
void
-dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
+dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction direction)
Synchronise a single contiguous or scatter/gather mapping for the CPU
--
2.1.0.231.g7484e3b
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