From 7cdcc8e4762f0e4a94cead6a3b57b5eaa01bd5da Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Date: Wed, 26 May 2010 14:44:21 -0700 Subject: [PATCH] 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> --- Documentation/DMA-API-HOWTO.txt | 4 ++++ 1 file changed, 4 insertions(+) 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