From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Belay Date: Sun, 01 May 2005 22:16:37 +0000 Subject: Re: [patch] properly stop devices before poweroff Message-Id: <20050501221637.GE3951@neo.rr.com> List-Id: References: <20050421111346.GA21421@elf.ucw.cz> <20050429061825.36f98cc0.akpm@osdl.org> <42752954.5050600@jp.fujitsu.com> In-Reply-To: <42752954.5050600@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Kenji Kaneshige , greg@kroah.org Cc: Andrew Morton , Pavel Machek , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org On Mon, May 02, 2005 at 04:09:08AM +0900, Kenji Kaneshige wrote: > Hi, > > Andrew Morton wrote: > >Pavel Machek wrote: > > > >> > >>Without this patch, Linux provokes emergency disk shutdowns and > >>similar nastiness. It was in SuSE kernels for some time, IIRC. > >> > > > > > >With this patch when running `halt -p' my ia64 Tiger (using > >tiger_defconfig) gets a stream of badnesses in iosapic_unregister_intr() > >and then hangs up. > > > >Unfortunately it all seems to happen after the serial port has been > >disabled because nothing comes out. I set the console to a squitty font > >and took a piccy. See > >http://www.zip.com.au/~akpm/linux/patches/stuff/dsc02505.jpg > > > >I guess it's an ia64 problem. I'll leave the patch in -mm for now. > > > > I guess the stream of badness was occured as follows: > > pcibios_disable_device() for ia64 assumes that pci_enable_device() > and pci_disable_device() are balanced. But with 'properly stop > devices before power off' patch, pci_disable_device() becomes to be > called twice for e1000 device at halt time, through reboot_notifier_list > callback and through device_suspend(). As a result, > iosapic_unregister_intr() > was called for already unregistered gsi and then stream of badness > was displayed. > > I think the following patch will remove this stream of badness. I'm > sorry but I have not checked if the stream of badness is actually > removed because I'm on vacation and I can't look at my display > (I'm working via remote console). Could you try this patch? > > By the way, I don't think this stream of badness is related to hang up, > because the problem (hang up) was reproduced even on my test kernel that > doesn't call pcibios_disable_device(). > > Thanks, > Kenji Kaneshige > --- > > > There might be some cases that pci_disable_device() is called even if > the device is already disabled. In this case, pcibios_disable_device() > should not call acpi_pci_irq_disable() for the device. > > Signed-off-by: Kenji Kaneshige > Although this would solve the problem, it may or may not be the right thing to do. The bug is not in pci_disable_device(), it's in the fact that we're calling pci_disable_device() twice. Whether pci_disable_device() should ignore this or create an error is an implementation decision. It might make sense to have it print a warning. Greg, what are your thoughts? What's important is that we don't want to suspend the device twice (in this case suspend and reboot_notifier). Thanks, Adam