korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-15 06:55:13 +08:00
Code Issues Packages Projects Releases Wiki Activity

[AVR32] Make dma_sync_*_for_cpu no-ops

Browse Source 
I don't think the dma_sync_*_for_cpu ever did anything useful. We
flush the relevant cache lines when mapping the buffer or when calling
dma_sync_*_for_device(), and the CPU isn't allowed to touch the buffer
after that.

In other words, if these functions actually have anything to flush
from the caches, we're already in trouble.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This commit is contained in:
Haavard Skinnemoen 2007-09-07 16:00:25 +01:00
parent 0d2372e5d6
commit b5a8e7362a
1 changed files with 10 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
include/asm-avr32/dma-mapping.h
View File

@ -264,7 +264,11 @@ static inline void
dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction)
{
dma_cache_sync(dev, bus_to_virt(dma_handle), size, direction);
/*
* No need to do anything since the CPU isn't supposed to
* touch this memory after we flushed it at mapping- or
* sync-for-device time.
*/
}
static inline void
@ -309,12 +313,11 @@ static inline void
dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction)
{
int i;
for (i = 0; i < nents; i++) {
dma_cache_sync(dev, page_address(sg[i].page) + sg[i].offset,
sg[i].length, direction);
}
/*
* No need to do anything since the CPU isn't supposed to
* touch this memory after we flushed it at mapping- or
* sync-for-device time.
*/
}
static inline void