X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=Documentation%2FDMA-mapping.txt;h=c74fec8c2351168d1329c527183f3a975234030e;hb=54cbc9abe57cf0a36619f394802448c62402599a;hp=b49427aa8510f5fe080613ce5304cbf9ae3cc345;hpb=819e32377e401669d2c010f1a0ce12fe43ea5261;p=safe%2Fjmp%2Flinux-2.6 diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt index b49427a..c74fec8 100644 --- a/Documentation/DMA-mapping.txt +++ b/Documentation/DMA-mapping.txt @@ -317,9 +317,9 @@ you should do: cpu_addr = pci_alloc_consistent(pdev, size, &dma_handle); -where pdev is a struct pci_dev *. You should pass NULL for PCI like buses -where devices don't have struct pci_dev (like ISA, EISA). This may be -called in interrupt context. +where pdev is a struct pci_dev *. This may be called in interrupt context. +You should use dma_alloc_coherent (see DMA-API.txt) for buses +where devices don't have struct pci_dev (like ISA, EISA). This argument is needed because the DMA translations may be bus specific (and often is private to the bus which the device is attached @@ -332,7 +332,7 @@ __get_free_pages (but takes size instead of a page order). If your driver needs regions sized smaller than a page, you may prefer using the pci_pool interface, described below. -The consistent DMA mapping interfaces, for non-NULL dev, will by +The consistent DMA mapping interfaces, for non-NULL pdev, will by default return a DMA address which is SAC (Single Address Cycle) addressable. Even if the device indicates (via PCI dma mask) that it may address the upper 32-bits and thus perform DAC cycles, consistent @@ -740,7 +740,7 @@ failure can be determined by: dma_addr_t dma_handle; dma_handle = pci_map_single(pdev, addr, size, direction); - if (pci_dma_mapping_error(dma_handle)) { + if (pci_dma_mapping_error(pdev, dma_handle)) { /* * reduce current DMA mapping usage, * delay and try again later or