Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933976AbbELXFQ (ORCPT ); Tue, 12 May 2015 19:05:16 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:56862 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753969AbbELXFL (ORCPT ); Tue, 12 May 2015 19:05:11 -0400 From: "Rafael J. Wysocki" To: Sander Eikelenboom Cc: Konrad Rzeszutek Wilk , rafael.j.wysocki@intel.com, linux-acpi@vger.kernel.org, David Vrabel , xen-devel , linux-kernel@vger.kernel.org Subject: Re: Regression due to "device property: Make it possible to use secondary firmware nodes" Re: Xen-unstable + linux 4.1-mergewindow: problems with PV guest pci passthrough: pcifront pci-0: pciback not responding!!! Date: Wed, 13 May 2015 01:30:20 +0200 Message-ID: <5850287.piKO3Xp1SW@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.0.0+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <238309395.20150513005236@eikelenboom.it> References: <135105791.20150427174800@eikelenboom.it> <3477983.pEhNuQXIjK@vostro.rjw.lan> <238309395.20150513005236@eikelenboom.it> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7503 Lines: 155 On Wednesday, May 13, 2015 12:52:36 AM Sander Eikelenboom wrote: > > Tuesday, May 12, 2015, 5:45:06 PM, you wrote: > > > On Tuesday, May 12, 2015 02:59:57 AM Rafael J. Wysocki wrote: > >> On Monday, May 11, 2015 11:20:29 AM Konrad Rzeszutek Wilk wrote: > >> > On Tue, May 05, 2015 at 12:18:49AM +0200, Sander Eikelenboom wrote: > >> > > Hello Sander, > >> > > > >> > > Monday, April 27, 2015, 5:48:00 PM, you wrote: > >> > > > >> > > > Hi David / Konrad, > >> > > > >> > > > Here the other problem i found, which is introduced somewhere in the > >> > > > 4.1 mergewindow: > >> > > > >> > > > on 4.1.0-rc1 (with the one revert to get things booting) i get this in > >> > > > the PV Guest console: > >> > > > >> > > > [ 0.517392] crc32c_combine: 8373 self tests passed > >> > > > [ 0.517608] pci_hotplug: PCI Hot Plug PCI Core version: 0.5 > >> > > > [ 0.517655] pciehp: PCI Express Hot Plug Controller Driver version: 0.4 > >> > > > [ 0.517677] cpcihp_generic: Generic port I/O CompactPCI Hot Plug Driver version: 0.1 > >> > > > [ 0.517684] cpcihp_generic: not configured, disabling. > >> > > > [ 0.517700] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4 > >> > > > [ 0.517713] acpiphp_ibm: ibm_acpiphp_init: acpi_walk_namespace failed > >> > > > [ 0.519849] usbcore: registered new interface driver udlfb > >> > > > [ 0.613289] xen:xen_evtchn: Event-channel device installed > >> > > > [ 0.613436] pcifront pci-0: Installing PCI frontend > >> > > > [ 0.613578] pcifront pci-0: Creating PCI Frontend Bus 0000:00 > >> > > > [ 0.613616] pcifront pci-0: PCI host bridge to bus 0000:00 > >> > > > [ 0.613624] pci_bus 0000:00: root bus resource [io 0x0000-0xffff] > >> > > > [ 0.613631] pci_bus 0000:00: root bus resource [mem 0x00000000-0xffffffffffff] > >> > > > [ 0.613638] pci_bus 0000:00: root bus resource [bus 00-ff] > >> > > > [ 0.616672] pcifront pci-0: pciback not responding!!! > >> > > > [ 2.613762] clocksource tsc: mask: 0xffffffffffffffff max_cycles: 0x2e20fd6f2ba, max_idle_ns: 440795302556 ns > >> > > > [ 2.614275] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled > >> > > > [ 2.614682] Linux agpgart interface v0.103 > >> > > > [ 2.614731] Hangcheck: starting hangcheck timer 0.9.1 (tick is 180 seconds, margin is 60 seconds). > >> > > > [ 2.614762] [drm] Initialized drm 1.1.0 20060810 > >> > > > [ 2.614789] [drm] radeon kernel modesetting enabled. > >> > > > [ 2.616529] brd: module loaded > >> > > > [ 2.617844] loop: module loaded > >> > > > [ 2.620008] pcifront pci-0: pciback not responding!!! > >> > > > [ 4.621490] pcifront pci-0: pciback not responding!!! > >> > > > [ 6.621866] pcifront pci-0: pciback not responding!!! > >> > > > [ 8.622421] pcifront pci-0: pciback not responding!!! > >> > > > etc. etc. etc. > >> > > > >> > > > >> > > > Where on 4.0.0 it get: > >> > > > >> > > > [ 0.442554] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4 > >> > > > [ 0.442583] acpiphp_ibm: ibm_acpiphp_init: acpi_walk_namespace failed > >> > > > [ 0.443293] pcifront pci-0: Allocated pdev @ 0xffff88001ab23c00 pdev->sh_info @ 0xffff88001937f000 > >> > > > [ 0.444885] pcifront pci-0: publishing successful! > >> > > > [ 0.445302] usbcore: registered new interface driver udlfb > >> > > > [ 0.445829] xen:xen_evtchn: Event-channel device installed > >> > > > [ 0.446499] pcifront pci-0: Installing PCI frontend > >> > > > [ 0.446715] pcifront pci-0: Creating PCI Frontend Bus 0000:00 > >> > > > [ 0.446951] pcifront pci-0: PCI host bridge to bus 0000:00 > >> > > > [ 0.446960] pci_bus 0000:00: root bus resource [io 0x0000-0xffff] > >> > > > [ 0.446968] pci_bus 0000:00: root bus resource [mem 0x00000000-0xffffffffffff] > >> > > > [ 0.446988] pci_bus 0000:00: root bus resource [bus 00-ff] > >> > > > [ 0.447002] pci_bus 0000:00: scanning bus > >> > > > [ 0.447140] pci 0000:00:00.0: [13f6:0111] type 00 class 0x040100 > >> > > > [ 0.447520] pci 0000:00:00.0: reg 0x10: [io 0x7800-0x78ff] > >> > > > [ 0.449148] pci 0000:00:00.0: supports D1 D2 > >> > > > [ 0.449791] pci_bus 0000:00: fixups for bus > >> > > > [ 0.449794] pci_bus 0000:00: bus scan returning with max=00 > >> > > > [ 0.450604] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled > >> > > > [ 0.451991] Linux agpgart interface v0.103 > >> > > > [ 0.452160] Hangcheck: starting hangcheck timer 0.9.1 (tick is 180 seconds, margin is 60 seconds). > >> > > > [ 0.452222] [drm] Initialized drm 1.1.0 20060810 > >> > > > [ 0.452300] [drm] radeon kernel modesetting enabled. > >> > > > [ 0.462384] pcifront pci-0: claiming resource 0000:00:00.0/0 > >> > > > >> > > > But i thought the patches that would change pci bus scanning were destined for > >> > > > 4.2 though ... > >> > > > >> > > > -- > >> > > > Sander > >> > > > >> > > Hi David / Konrad, > >> > > > >> > > I have bisected this one .. it leads to: > >> > > > >> > > commit 97badf873ab60e841243b66133ff9eff2a46ef29 > >> > > Author: Rafael J. Wysocki > >> > > Date: Fri Apr 3 23:23:37 2015 +0200 > >> > > > >> > > device property: Make it possible to use secondary firmware nodes > >> > > > >> > > Since i didn't see it directly related to pci-front, i double checked by > >> > > reverting this commit(and 9b73262ccbf2fb0060303f047863214269e64f9a since it > >> > > build depends on the other) on 4.1-rc2. > >> > > > >> > > Reverting in the guest kernel indeed makes pci-front work correct again. > >> > > >> > That is quite odd. > >> > >> Yes, that's weird. > >> > >> > And sadly I am due for vacation at the end of this week > >> > so own't be able to look at this (and prepare an debug patch for the MSI > >> > addendum debug patch either). > >> > > >> > > >> > Rafael, > >> > > >> > Were there any other bug reports about this particular commit? > >> > >> Not that I'm aware of. > >> > >> I'll look at that tomorrow when I'm a bit less tired. > > > So since device_add_property_set() is not currently used, the commit it's > > been bisected to should not have any functional effects on anything, but > > nevertheless please apply the appended debug patch and see if you get any > > extra output from it. > > > That said, the commit might make a difference for Xen if there's an already > > existing initialization ordering issue, because it slows down the ACPI/PCI > > initialization a bit (due to the new checks in set_primary_fwnode()) and > > something already racy with respect to it may be able to win the race now. > > > So I'm wondering, for example, if adding something like msleep(100); at the > > beginning of pcifront_init() (right after the initial checks) will make any > > difference. > > Hi Rafael, > > The WARN's don't trigger, so it's a red herring i suppose :-( It seems so. The commit also changes the size of struct acpi_device, but that shouldn't matter. > I also tried the msleep(100), but that didn't change anything as well. I see. Well, I'm not really familiar with the Xen-related code, so it is hard to me to give you any useful advice here. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/