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| author | Tony Lindgren <tony@atomide.com> | 2015-11-12 09:58:21 -0800 |
|---|---|---|
| committer | Tony Lindgren <tony@atomide.com> | 2015-11-12 09:58:21 -0800 |
| commit | ff6d03b9d9cad592320ce21e9b22befe56ebe6b6 (patch) | |
| tree | da02d83177a107f92c446dbf7a93bdc1bac96cdf /Documentation/DMA-API-HOWTO.txt | |
| parent | 7ef71b70e18a82bb363905f72672317d0e1e8810 (diff) | |
| parent | 469689a45f78505d864210b3a5d75404eb7f24ee (diff) | |
Merge branch 'x15-audio-fixes' into omap-for-v4.4/fixes
Diffstat (limited to 'Documentation/DMA-API-HOWTO.txt')
| -rw-r--r-- | Documentation/DMA-API-HOWTO.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index 55b70b903ead..d69b3fc64e14 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 |