From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [RFC] IDE/ATA/SATA controller hotplug Date: Wed, 11 Aug 2004 15:33:06 -0400 Sender: linux-ide-owner@vger.kernel.org Message-ID: <411A7472.9010606@pobox.com> References: <200407272018.i6RKIiYB028210@falcon10.austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:10417 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S268012AbUHKTdV (ORCPT ); Wed, 11 Aug 2004 15:33:21 -0400 In-Reply-To: <200407272018.i6RKIiYB028210@falcon10.austin.ibm.com> List-Id: linux-ide@vger.kernel.org To: Doug Maxey Cc: Linux IDE Mailing List , Linux Kernel Mailing List Doug Maxey wrote: > On Tue, 27 Jul 2004 11:31:15 EDT, Jeff Garzik wrote: >>> What I would like is input on the general strategy that should be >>> taken to modify the controller/adapter and device stack to: >>> >>> 1) be first class modules, where all controllers/adapters are >>> capable of being loaded and unloaded. This is directed mostly at >>> IDE/Southbridge controller/adapter devices. >> >>this is already the case in IDE and libata > > > I would have to differ with you here. From conversations and fairly > (2 or 3 months ago) experience, the IDE core is not capable of being > unloaded. As long as the low-level driver can be unloaded, that's sufficient for hardware- and device-hotplug. >>> 2) extend that support to all child devices; disk, optical, >>> and tape. >> >>this is already the case in IDE and SCSI > > > Educational question, what would I be looking for when grokking code > to see this is in place? Just general refcounting / module support code. >>> 3) be part of mainline. >> >>this is already the case > > > Yes, the drivers are in the mainline. Just not sure of how many > platforms will have non-pluggable controllers that need to have them > hot-plugged. :-) The PCI API is a hotplug API. Whether the underlying controller is hotpluggable or not is largely irrelevant to low-level drivers. >>> The items I perceive at the top of the issue list are: >>> >>> - The primary platforms for IDE/ATA devices are x86 based, and >>> certainly do not care about having this capability. >> >>incorrect > > > Ok, please delineate. Working off the assumption that 95+% of the > systems that run Linux are x86 based, and have a single partition for > the system. In other words, no virtual processors, where each is > totally separate from the other. That's completely irrelevant. libata and the IDE core work without change on x86 and non-x86 systems. >>> - Where should this capability go? Fork a subset of IDE >>> controllers, and put them under the arch specific dir? >>> Or include all devices? >> >>there is nothing arch-specific about this > > > Again, going back to my original premise, that is, which platforms do > you foresee needing this capability? I know that all should have > eventually. All platforms should be considered hotplug. Jeff