From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: on patch "[SCSI] relax scsi dma alignment" Date: Sat, 26 Jan 2008 12:54:02 -0600 Message-ID: <1201373642.4387.0.camel@localhost.localdomain> References: <479B80A3.5070207@s5r6.in-berlin.de> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from accolon.hansenpartnership.com ([76.243.235.52]:37202 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776AbYAZSyI (ORCPT ); Sat, 26 Jan 2008 13:54:08 -0500 In-Reply-To: <479B80A3.5070207@s5r6.in-berlin.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Stefan Richter Cc: linux1394-devel@lists.sourceforge.net, linux-scsi@vger.kernel.org On Sat, 2008-01-26 at 19:49 +0100, Stefan Richter wrote: > On commit 465ff3185e0cb76d46137335a4d21d0d9d3ac8a2: > > This patch relaxes the default SCSI DMA alignment from 512 bytes to 4 > > bytes. I remember from previous discussions that usb and firewire have > > sector size alignment requirements, so I upped their alignments in the > > respective slave allocs. > [...] > > drivers/ata/libata-scsi.c | 5 ++++- > > drivers/firewire/fw-sbp2.c | 6 ++++++ > > drivers/ieee1394/sbp2.c | 6 ++++++ > > drivers/scsi/scsi_lib.c | 8 ++++++++ > > drivers/usb/storage/scsiglue.c | 20 ++++++++++---------- > > 5 files changed, 34 insertions(+), 11 deletions(-) > > No, FireWire only requires 4 bytes alignment. > > I will channel a reversion of the firewire and ieee1394 hunks through > linux1394-2.6.git for 2.6.26. Don't revert, just put the numbers down to 4 (just in case someone decides to lower the default SCSI alignment down from four ...). James