From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MGcmt-00019d-GF for qemu-devel@nongnu.org; Tue, 16 Jun 2009 13:49:35 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MGcmo-00017v-Sl for qemu-devel@nongnu.org; Tue, 16 Jun 2009 13:49:34 -0400 Received: from [199.232.76.173] (port=34125 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MGcmo-00017p-Nm for qemu-devel@nongnu.org; Tue, 16 Jun 2009 13:49:30 -0400 Received: from mx2.redhat.com ([66.187.237.31]:58182) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MGcmo-0001Gh-8e for qemu-devel@nongnu.org; Tue, 16 Jun 2009 13:49:30 -0400 Date: Tue, 16 Jun 2009 20:47:25 +0300 From: Gleb Natapov Subject: Re: [Qemu-devel] Register uhci_reset() callback. Message-ID: <20090616174725.GG782@redhat.com> References: <20090611084808.GA19508@redhat.com> <20090616152050.GD782@redhat.com> <200906161754.59643.paul@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200906161754.59643.paul@codesourcery.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: Blue Swirl , qemu-devel@nongnu.org, Avi Kivity On Tue, Jun 16, 2009 at 05:54:54PM +0100, Paul Brook wrote: > On Tuesday 16 June 2009, Gleb Natapov wrote: > > On Tue, Jun 16, 2009 at 06:14:51PM +0300, Blue Swirl wrote: > > > > Because interrupt line is stuck a guest can't get to the point where it > > > > loads a driver to the second device. For outside observer the guest > > > > just hangs. > > > > > > I see. The problem is in piix_pci interrupt handling, pci_irq_levels[] > > > should be set to zero on reset. > > > > The patch that does that was rejected earlier :) > > http://lists.gnu.org/archive/html/qemu-devel/2009-06/msg00342.html > > http://lists.gnu.org/archive/html/qemu-devel/2009-06/msg00344.html > > You're both wrong. > As always. > If allow devices to be reset independently then they should probably set theit > IRQ output on reset. It is not "if" it is "when". We have to allow device to be reset independently for hot-unplug. The reset mechanism of qemu is not sophisticated to do that yet. This should be a part of a device model. So I take this statement of yours as if you agree that each device should reset its irq line. Good. > > IRQ muxes (e.g. PCI busses) should handle reseting and save/restore of their > own internal state. Here are patches. You are welcome to commit them: http://lists.gnu.org/archive/html/qemu-devel/2009-06/msg00342.html http://lists.gnu.org/archive/html/qemu-devel/2009-06/msg00344.html > Devices should not cause IRQ state changes on restore. Commit 3dcd219f is > incorrect. > Don't agree or disagree on this. Haven't thought about it much. -- Gleb.