From c2282adbdea3548ae0271c1b1b2deec5f56ad224 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Mon, 8 Mar 2010 09:11:07 +0100 Subject: [PATCH] Documentation: fix block/biodoc.txt dma mapping description - It looks incorrect to use blk_rq_map_sg with pci_map_page here about DMA mappings. dma_map_sg? - better to use dma_map_page instead of pci_map_page. http://marc.info/?l=linux-kernel&m=126596737604808&w=2 Signed-off-by: FUJITA Tomonori Signed-off-by: Jens Axboe --- Documentation/block/biodoc.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 6fab97e..508b5b2 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -1162,8 +1162,8 @@ where a driver received a request ala this before: As mentioned, there is no virtual mapping of a bio. For DMA, this is not a problem as the driver probably never will need a virtual mapping. -Instead it needs a bus mapping (pci_map_page for a single segment or -use blk_rq_map_sg for scatter gather) to be able to ship it to the driver. For +Instead it needs a bus mapping (dma_map_page for a single segment or +use dma_map_sg for scatter gather) to be able to ship it to the driver. For PIO drivers (or drivers that need to revert to PIO transfer once in a while (IDE for example)), where the CPU is doing the actual data transfer a virtual mapping is needed. If the driver supports highmem I/O, -- 2.7.4