From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755254Ab3H3LU0 (ORCPT ); Fri, 30 Aug 2013 07:20:26 -0400 Received: from charlotte.tuxdriver.com ([70.61.120.58]:60316 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754264Ab3H3LUX (ORCPT ); Fri, 30 Aug 2013 07:20:23 -0400 Date: Fri, 30 Aug 2013 07:20:13 -0400 From: Neil Horman To: Bjorn Helgaas Cc: linux-kernel@vger.kernel.org, Len Brown , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH v4] ACPI: Fix osc flag setup ordering to allow pcie hotplug use when available Message-ID: <20130830112013.GA1142@hmsreliant.think-freely.org> References: <1377278379-9054-1-git-send-email-nhorman@tuxdriver.com> <1377807425-27423-1-git-send-email-nhorman@tuxdriver.com> <20130829234052.GA22252@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130829234052.GA22252@google.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Score: -2.9 (--) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 29, 2013 at 05:40:52PM -0600, Bjorn Helgaas wrote: > On Thu, Aug 29, 2013 at 04:17:05PM -0400, Neil Horman wrote: > > This is a fix for: > > https://bugzilla.kernel.org/show_bug.cgi?id=60736 > > > > During the 3.8 devel cycle: > > > > commit 8c33f51df406e1a1f7fa4e9b244845b7ebd61fa6 > > Author: Taku Izumi > > Date: Tue Oct 30 15:27:13 2012 +0900 > > > > PCI/ACPI: Request _OSC control before scanning PCI root bus > > > > went in to allow us to query the pcie hotplug flags during the acpi bus scan. > > It however caused problems with the disabling of pcie aspm, and so: > > commit b8178f130e25c1bdac1c33e0996f1ff6e20ec08e > > Author: Bjorn Helgaas > > Date: Mon Apr 1 15:47:39 2013 -0600 > > > > Revert "PCI/ACPI: Request _OSC control before scanning PCI root bus" > > > > Backed it out. This of course brought back the problem in which acpi took over > > hotplug ports that were meant to be controlled by pcie. > > > > This patch gives us both items. It lets us request _OSC control before scanning > > the pci root bus, but defers any disabling of aspm until after the scan is > > complete, allowing us to properly handle old pcie 1.1 devices aspm settings > > properly, as b8178f130e documents. > > > > Tested successfully by myself. > > > > Signed-off-by: Neil Horman > > CC: Len Brown > > CC: "Rafael J. Wysocki" > > CC: linux-acpi@vger.kernel.org > > CC: linux-pci@vger.kernel.org > > I added Yinghai's ack and a stable tag and put this in pci/misc > for v3.12. Thanks! > > I reworked the changelog because I think the actual cause of the > regression was 3b63aaa70e, not the _OSC commits you mentioned: > > 8c33f51df4 ("PCI/ACPI: Request _OSC control before scanning PCI root bus") > appeared in v3.8 and broke ASPM but not acpiphp. > > b8178f130e ('Revert "PCI/ACPI: Request _OSC control before scanning PCI > root bus"') appeared in v3.9 and fixed ASPM, leaving acpiphp working. > > 3b63aaa70e ("PCI: acpiphp: Do not use ACPI PCI subdriver mechanism") > appeared in v3.10, and I believe this is what actually broke acpiphp > because it moved the acpiphp initialization earlier, into the bus scan. > > in v3.8: > acpi_pci_root_add > acpi_pci_osc_control_set # request OS control > pci_acpi_scan_root # scan bus > acpi_pci_root_start > add_bridge # acpi_pci_driver .add method > ... > device_is_managed_by_native_pciehp # OK > > in v3.9: > acpi_pci_root_add > pci_acpi_scan_root # scan bus > acpi_pci_osc_control_set # request OS control > add_bridge # acpi_pci_driver .add method > ... > device_is_managed_by_native_pciehp # OK > > in v3.10: > acpi_pci_root_add > pci_acpi_scan_root # scan bus > ... > acpiphp_enumerate_slots > ... > device_is_managed_by_native_pciehp # PROBLEM > acpi_pci_osc_control_set # request OS control > > So I added a stable tag for v3.10+ only. I'll ask Linus to merge it > directly during the merge window for v3.12, and hopefully it will be > backported to the v3.10 and v3.11 stable trees soon after that. > > Bjorn > Copy that, thanks! Neil