From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 04/14] libata-hp-prep: update ata_scsi_find_dev() and friends Date: Fri, 26 May 2006 03:07:10 -0400 Message-ID: <4476A91E.2040900@pobox.com> References: <11480445841836-git-send-email-htejun@gmail.com> <446DDE41.9040900@pobox.com> <44731B68.6050803@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:60099 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S1751328AbWEZHHZ (ORCPT ); Fri, 26 May 2006 03:07:25 -0400 In-Reply-To: <44731B68.6050803@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: mlord@pobox.com, albertcc@tw.ibm.com, alan@lxorguk.ukuu.org.uk, axboe@suse.de, forrest.zhao@intel.com, linux-ide@vger.kernel.org Tejun Heo wrote: > Jeff Garzik wrote: >> Tejun Heo wrote: >>> Separate out ata_find_dev() and __ata_scsi_find_dev() from >>> ata_scsi_find_dev(). ata_find_dev() checks ATA_FLAG_SLAVE_POSS for >>> id==1 case, so all three functions return NULL if id==1 is specified >>> for !SLAVE_POSS port. These will be used by later hotplug >>> implementation. >>> >>> Signed-off-by: Tejun Heo >> >> ACK with future comment: >> >> Once we have a better way to sequence simplex + master/slave + normal >> SATA, libata-scsi should move to exporting one Scsi_Host per >> controller, with each physical ATA bus being a scsi channel. > > I think the 'better way' would be implemented after we move to new block > infrastructure (libstorage). libstroage will probably deal with the > mentioned command scheduling with queue grouping and associated > scheduling mechanism, and SCSI mapping will be done by SATL. Although > mapping port id to channel fits better, I'm not sure whether the > conversion would be worthwhile at that point. It wouldn't make any > functional difference but the change would be visible to userspace. > > If we're gonna do that, how about piggybacking ataX -> ataX-1 change > with/around it? It also is a user-visible change and the magnitude of > affect on user space would be similar. Sure... Jeff