From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian King Subject: Re: [RFC 0/2] libata: support SATA devices on SAS HBAs Date: Tue, 25 Oct 2005 12:57:23 -0500 Message-ID: <435E7203.8020008@us.ibm.com> References: <4341A91A.3020000@us.ibm.com> <434251E0.9060000@pobox.com> <58cb370e0510040322q1cb7a13bjfc6c7875140d20a9@mail.gmail.com> <58cb370e0510041356h780e7a5aifda0c232f677471e@mail.gmail.com> <43443E99.4090008@pobox.com> Reply-To: brking@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from e1.ny.us.ibm.com ([32.97.182.141]:22729 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id S932275AbVJYR5Z (ORCPT ); Tue, 25 Oct 2005 13:57:25 -0400 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e1.ny.us.ibm.com (8.12.11/8.12.11) with ESMTP id j9PHvO7h030707 for ; Tue, 25 Oct 2005 13:57:24 -0400 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay04.pok.ibm.com (8.12.10/NCO/VERS6.7) with ESMTP id j9PHvOHM071484 for ; Tue, 25 Oct 2005 13:57:24 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.12.11/8.13.3) with ESMTP id j9PHvOh0031576 for ; Tue, 25 Oct 2005 13:57:24 -0400 In-Reply-To: <43443E99.4090008@pobox.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: Bartlomiej Zolnierkiewicz , linux-ide@vger.kernel.org Jeff Garzik wrote: > Bartlomiej Zolnierkiewicz wrote: > >>[PATCH] libata: add ops->qc_transport for SAS >> >>* add ->qc_transport to struct ata_port_operations >>* add default ata_qc_transport() and update all host drivers >> >>Thanks to this change we won't have to depend on host_set >>and host_set->lock for devices attached to SAS HBAs. >> >>Signed-off-by: Bartlomiej Zolnierkiewicz > > > > Seems sane at a quick glance, though I'm a bit disappointed we have to > add yet another level of indirection to the hot path. > > You made a good point, though, by pointing out that all the ata_qc_xxx > stuff is essentially completely inside a single lock domain. > > Other notes: There may be other dependencies such as wanting to > reference the struct device pointer in host_set and similar details that > need handling. Also, I was planning to move some of the ata_port_ops > into a separate host_set ops, since they (hooks such as ->irq_clear or > ->host_stop) are really host-wide hooks, not per-port hooks. Jeff, Is this patch on its way into one of your trees, or should I just pick it up add it to my libata SAS patchset so you can just grab the whole patchset once it is ready? Brian -- Brian King eServer Storage I/O IBM Linux Technology Center