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>
This commit is contained in:
FUJITA Tomonori 2010-05-26 14:44:21 -07:00 committed by Linus Torvalds
parent 99d1bd2c13
commit 7cdcc8e476
1 changed files with 4 additions and 0 deletions

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@ -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