From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: Xen 4 serial hangs during boot Date: Thu, 26 Jul 2012 10:36:22 -0400 Message-ID: <20120726143622.GF28024@phenom.dumpdata.com> References: <500DB9CD.5060900@theshore.net> <500E95D30200007800090218@nat28.tlf.novell.com> <20120726135001.GA28024@phenom.dumpdata.com> <50116BF102000078000909D1@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <50116BF102000078000909D1@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: Andrew Cooper , xen devel , Keir Fraser List-Id: xen-devel@lists.xenproject.org On Thu, Jul 26, 2012 at 03:10:25PM +0100, Jan Beulich wrote: > >>> On 26.07.12 at 15:50, Konrad Rzeszutek Wilk wrote: > > Then recently (yesterday?) the upstream kernel started doing something > > wonky on this card: > > > > 01:05.0 Serial controller: NetMos Technology PCI 9835 Multi-I/O Controller > > (rev 01) > > Under Xen, when it boots it hits right here: > > [ 1.240774] pci 0000:01:05.0: [9710:9835] type 00 class 0x070002 > > and then stops [note: I hadn't really done any investigation to see > > if the machine is dead or if it continues on, but with the serial port just > > wedged hard]. > > The machine state here, if accessible at all, would of course be > very interesting. Hope to get to that today. > > > On baremetal it can actually read the IO bars: > > [ 1.240774] pci 0000:01:05.0: [9710:9835] type 00 class 0x070002 > > [ 1.247075] pci 0000:01:05.0: reg 10: [io 0xe050-0xe057] > > [ 1.252734] pci 0000:01:05.0: reg 14: [io 0xe040-0xe047] > > [ 1.258394] pci 0000:01:05.0: reg 18: [io 0xe030-0xe037] > > [ 1.264054] pci 0000:01:05.0: reg 1c: [io 0xe020-0xe027] > > [ 1.269713] pci 0000:01:05.0: reg 20: [io 0xe010-0xe017] > > [ 1.275372] pci 0000:01:05.0: reg 24: [io 0xe000-0xe00f] > > > > so I am wondering if the back-ports in Xen 4.1 for dealing with > > PCI have something to do with this? > > What backports are you thinking of? I just went through the titles > of everything since 4.1.2, and nothing that has "PCI" in it looks > in any way dangerous. I know :-( That is why I am thinking it might be the kernel, but when I did a git bisection I got an innocious Documentation patch. But then recently (say 3.5) has been doing some weird stuff in the PCI space (like it seems to have MSI's and BARs disabled - at least when using them with xen-pciback to hide them). > > Jan