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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2010-05-27 01:44:21 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 20:12:53 +0400
commit7cdcc8e4762f0e4a94cead6a3b57b5eaa01bd5da (patch)
treefb15134a3e3327f667f07d4dcc6bafe163fb2082 /Documentation/DMA-API-HOWTO.txt
parent99d1bd2c131b2da10cf451c69e5b8c51761a901b (diff)
downloadlinux-7cdcc8e4762f0e4a94cead6a3b57b5eaa01bd5da.tar.xz
Documentation: add SCSI drivers' mapping error handling to DMA-API-HOWTO
Add the concrete DMA mapping error handling for SCSI drivers on the queuecommand path. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/DMA-API-HOWTO.txt')
-rw-r--r--Documentation/DMA-API-HOWTO.txt4
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt
index 93d90870791c..a38ddadd208e 100644
--- a/Documentation/DMA-API-HOWTO.txt
+++ b/Documentation/DMA-API-HOWTO.txt
@@ -745,6 +745,10 @@ and return NETDEV_TX_OK if the DMA mapping fails on the transmit hook
(ndo_start_xmit). This means that the socket buffer is just dropped in
the failure case.
+SCSI drivers must return SCSI_MLQUEUE_HOST_BUSY if the DMA mapping
+fails in the queuecommand hook. This means that the SCSI subsystem
+passes the command to the driver again later.
+
Closing
This document, and the API itself, would not be in its current