From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: [PATCH 1/1] ipr: Fix HDIO_GET_IDENTITY oops for SATA devices Date: Mon, 2 Jun 2008 20:53:29 +0100 Message-ID: <20080602205329.3b824d0b@core> References: <12124164141515-patch-mail.ibm.com> <48441AEE.6050605@garzik.org> <48441F82.6060706@linux.vnet.ibm.com> <1212425124.3369.20.camel@localhost.localdomain> <4844312C.7010403@garzik.org> <1212429428.3369.45.camel@localhost.localdomain> <484437C3.8020306@garzik.org> <1212435308.3369.58.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:35706 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751153AbYFBUR4 (ORCPT ); Mon, 2 Jun 2008 16:17:56 -0400 In-Reply-To: <1212435308.3369.58.camel@localhost.localdomain> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Jeff Garzik , brking@linux.vnet.ibm.com, linux-scsi@vger.kernel.org, thlin@linux.vnet.ibm.com, linux-ide@vger.kernel.org, miltonm@bga.com, Tejun Heo > I think it's possible to do the shift while still making it look to > single port hosts that nothing has changed There are very few of those. Your generic PC controller is single host, dual channel two devices per channel. > Well, we can be elastic on this. The common case is a two port > master/slave, isn't it. This particular one could just be treated as > two separate interfaces and hence two hosts (it's reasonably analagous > to the 53c896---which is a single chip that presents two SCSI channels > as two PCI functions). Not as trivial as you might hope. In some cases the two are closely linked, they often share timing rules. In other cases they have shared or single assignable DMA fifos. In practical terms that means you must reconfigure *both* channels when you do an EH. Alan