From 97a34eb77c758ff7821c2d29b3b5a84299c93aa1 Mon Sep 17 00:00:00 2001 From: Matti Linnanvuori Date: Mon, 28 Apr 2008 09:33:27 -0700 Subject: [PATCH] doc: fix an incorrect suggestion to pass NULL for PCI like buses Fix an incorrect suggestion to pass NULL to pci_alloc_consistent for PCI like buses where devices don't have struct pci_dev (like ISA, EISA). Signed-off-by: Matti Linnanvuori Acked-by: Matthew Wilcox Signed-off-by: Jesse Barnes --- Documentation/DMA-mapping.txt | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt index b49427aa85..d8347c1fd0 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 -- 2.39.5