X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=Documentation%2FDMA-mapping.txt;h=b463ecd0c7cebf36f53104015afcbeeccf4b934d;hb=4edc2f3416438a05b83a677ae7b1a78b3ca22bb9;hp=b49427aa8510f5fe080613ce5304cbf9ae3cc345;hpb=819e32377e401669d2c010f1a0ce12fe43ea5261;p=firefly-linux-kernel-4.4.55.git

diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt
index b49427aa8510..b463ecd0c7ce 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