summaryrefslogtreecommitdiffstats
path: root/Documentation/DMA-mapping.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/DMA-mapping.txt')
-rw-r--r--Documentation/DMA-mapping.txt12
1 files changed, 3 insertions, 9 deletions
diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt
index f4ac37f157ea..684557474c15 100644
--- a/Documentation/DMA-mapping.txt
+++ b/Documentation/DMA-mapping.txt
@@ -443,15 +443,9 @@ Only streaming mappings specify a direction, consistent mappings
implicitly have a direction attribute setting of
PCI_DMA_BIDIRECTIONAL.
-The SCSI subsystem provides mechanisms for you to easily obtain
-the direction to use, in the SCSI command:
-
- scsi_to_pci_dma_dir(SCSI_DIRECTION)
-
-Where SCSI_DIRECTION is obtained from the 'sc_data_direction'
-member of the SCSI command your driver is working on. The
-mentioned interface above returns a value suitable for passing
-into the streaming DMA mapping interfaces below.
+The SCSI subsystem tells you the direction to use in the
+'sc_data_direction' member of the SCSI command your driver is
+working on.
For Networking drivers, it's a rather simple affair. For transmit
packets, map/unmap them with the PCI_DMA_TODEVICE direction