From: Marek Szyprowski Date: Fri, 10 Feb 2012 18:55:20 +0000 (+0100) Subject: ARM: dma-mapping: remove offset parameter to prepare for generic dma_ops X-Git-Tag: sz_154~114 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4d3550e39c4f685ca83b0c5724be4e44c5eedbc1;p=pandora-kernel.git ARM: dma-mapping: remove offset parameter to prepare for generic dma_ops This patch removes the need for the offset parameter in dma bounce functions. This is required to let dma-mapping framework on ARM architecture to use common, generic dma_map_ops based dma-mapping helpers. Background and more detailed explaination: dma_*_range_* functions are available from the early days of the dma mapping api. They are the correct way of doing a partial syncs on the buffer (usually used by the network device drivers). This patch changes only the internal implementation of the dma bounce functions to let them tunnel through dma_map_ops structure. The driver api stays unchanged, so driver are obliged to call dma_*_range_* functions to keep code clean and easy to understand. The only drawback from this patch is reduced detection of the dma api abuse. Let us consider the following code: dma_addr = dma_map_single(dev, ptr, 64, DMA_TO_DEVICE); dma_sync_single_range_for_cpu(dev, dma_addr+16, 0, 32, DMA_TO_DEVICE); Without the patch such code fails, because dma bounce code is unable to find the bounce buffer for the given dma_address. After the patch the above sync call will be equivalent to: dma_sync_single_range_for_cpu(dev, dma_addr, 16, 32, DMA_TO_DEVICE); which succeeds. I don't consider this as a real problem, because DMA API abuse should be caught by debug_dma_* function family. This patch lets us to simplify the internal low-level implementation without chaning the driver visible API. Signed-off-by: Marek Szyprowski Acked-by: Kyungmin Park Tested-By: Subash Patel --- Reading git-diff-tree failed