Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759726Ab3EGVc4 (ORCPT ); Tue, 7 May 2013 17:32:56 -0400 Received: from mail-ie0-f180.google.com ([209.85.223.180]:38497 "EHLO mail-ie0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757572Ab3EGVcy (ORCPT ); Tue, 7 May 2013 17:32:54 -0400 Date: Tue, 7 May 2013 15:32:50 -0600 From: Bjorn Helgaas To: Yinghai Lu Cc: David Bulkow , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PCI: move down pci_fixup_final for hotplug path Message-ID: <20130507213250.GA22773@google.com> References: <5AA430FFE4486C448003201AC83BC85E03DEA379@EXHQ.corp.stratus.com> <1366940827-15336-1-git-send-email-yinghai@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1366940827-15336-1-git-send-email-yinghai@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4009 Lines: 105 On Thu, Apr 25, 2013 at 06:47:07PM -0700, Yinghai Lu wrote: > David found some resource conflict issue after > | PCI: Put pci_dev in device tree as early as possible > | commit 4f535093cf8f6da8cfda7c36c2c1ecd2e9586ee4 > > and > | USB: Fix handoff when BIOS disables host PCI device > | commit: cab928ee1f221c9cc48d6615070fefe2e444384a > > for usb qirks for hotplug path. > > After checking pci_fixup_device() with pci_fixup_final, > now we have different path for boot path and hotadd path. > > Boot path: because pci_apply_fix_final_quirks is not set yet, > so pci_fixup_device(pci_fixup_final) will be skipped > from pci_device_add(). > And later pci_apply_final_quirks will be called for all > pci devices via fs_initcall. > That is after pci_assign_unassign resource. > In that case quirk could use bars with problem. > > Hotadd path: pci_fixup_device(pci_fixup_final) will be executed > via pci_device_add(), and that is too early for hotplug > path, as pci bar for hot add devices is not assigned yet > after commit 4f535093. > > So we need to move down that for hotplug path, call that in > pci_bus_add_devices instead, as at that time just before > drivers get attached. > And that is simliar calling place for pci_device_add before > commit 4f535093 is applied. > > We should apply this fix for v3.9, but is too late now. > so get it into v3.10 and could get into v3.9 stable instead. > > Reported-by: David Bulkow > Tested-by: David Bulkow > Signed-off-by: Yinghai Lu I applied the following slightly tweaked patch to for-linus and will ask Linus to pull it for v3.10. Let me know if it looks OK. Bjorn commit a939563f3fd9cd6226c7fb7135d0b93507c53888 Author: Bjorn Helgaas Date: Tue May 7 14:35:44 2013 -0600 PCI: Delay final fixups until resources are assigned Commit 4f535093cf "PCI: Put pci_dev in device tree as early as possible" moved final fixups from pci_bus_add_device() to pci_device_add(). But pci_device_add() happens before resource assignment, so BARs may not be valid yet. Typical flow for hot-add: pciehp_configure_device pci_scan_slot pci_scan_single_device pci_device_add pci_fixup_device(pci_fixup_final, dev) # previous location # resource assignment happens here pci_bus_add_devices pci_bus_add_device pci_fixup_device(pci_fixup_final, dev) # new location [bhelgaas: changelog, move fixups to pci_bus_add_device()] Reference: https://lkml.kernel.org/r/20130415182614.GB9224@xanatos Reported-by: David Bulkow Tested-by: David Bulkow Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v3.9+ diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 748f8f3..32e66a6 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -174,6 +174,7 @@ int pci_bus_add_device(struct pci_dev *dev) * Can not put in pci_device_add yet because resources * are not assigned yet for some devices. */ + pci_fixup_device(pci_fixup_final, dev); pci_create_sysfs_dev_files(dev); dev->match_driver = true; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 43ece5d..67cd045 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1341,7 +1341,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) list_add_tail(&dev->bus_list, &bus->devices); up_write(&pci_bus_sem); - pci_fixup_device(pci_fixup_final, dev); ret = pcibios_add_device(dev); WARN_ON(ret < 0); -- 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/