From mboxrd@z Thu Jan 1 00:00:00 1970 From: Holger Macht Subject: Re: 2.6.25 semantic change in bay handling? Date: Tue, 6 May 2008 10:40:18 +0200 Message-ID: <20080506084018.GC8688@homac> References: <20080505223357.GA2839@srcf.ucam.org> <20080506081347.GA8688@homac> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.suse.de ([195.135.220.2]:54111 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755022AbYEFIif (ORCPT ); Tue, 6 May 2008 04:38:35 -0400 Content-Disposition: inline In-Reply-To: <20080506081347.GA8688@homac> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Matthew Garrett , linux-ide@vger.kernel.org, tejun@gmail.com, Jeff Garzik On Tue 06. May - 10:13:47, Holger Macht wrote: > On Mo 05. Mai - 23:33:57, Matthew Garrett wrote: > > 48feb3c419508487becfb9ea3afcc54c3eac6d80 appears to flag a device as > > detached if an acpi eject request is received. In 2.6.24 and earlier, an > > eject request merely sent an event to userland which could then cleanly > > unmount the device and let the user know when it was safe to remove the > > drive. Removing the device would then send another acpi request that > > triggered the actual hotplug and bus rescan. > > What second acpi request are you referring to? > > > This seems like a regression - it's no longer possible to ensure that a > > bay device is cleanly unmounted. Was this really the desired behaviour? > > I'm thinking about his for several days now and looking for a proper > solution how to ensure that userland has the possibility to cleanly > unmount a device. But it's definitely no regression. Before...systems with > a bay in a dock stations simply froze hard in certain circumstances. It > was pure luck that it worked for one major kernel version or so. > > The only sane way for me seems that userland has to be involved before > actually triggering any event or removing any device. Something like > "savely remove this piece of hardware". > > For this to archive, we would need another sysfs entry flagging a bay > device as "on dock station", so that userland knows what to unmount/eject > before a dock event. Userspace relying on the bay event on the device is > not a proper solution. The device may have been gone before userland > finishes his work, or as you mention, there's no bay event. > > > It should be noted that not all hardware sends the eject request at all > > (Thinkpads do, but Dell and HP laptops don't), so we can't depend on > > receiving this when dealing with a bay event. > > I don't think we depend on the event. If the device gets removed without > an appropriate event, the behaviour should be the same as before. If not, > that wasn't the intentional behaviour. AFAICT! I just saw that the initial mail was not explicitly meant for me and the patches regarding bay devices I've sent a couple of weeks ago. Regards, Holger