From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEC1EC5DF62 for ; Wed, 6 Nov 2019 12:28:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FF65217D7 for ; Wed, 6 Nov 2019 12:28:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728140AbfKFM2c (ORCPT ); Wed, 6 Nov 2019 07:28:32 -0500 Received: from cloudserver094114.home.pl ([79.96.170.134]:61985 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727391AbfKFM2c (ORCPT ); Wed, 6 Nov 2019 07:28:32 -0500 Received: from 79.184.254.83.ipv4.supernova.orange.pl (79.184.254.83) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.292) id 1cbb818cf7d190ce; Wed, 6 Nov 2019 13:28:28 +0100 From: "Rafael J. Wysocki" To: Mika Westerberg , Bjorn Helgaas Cc: Len Brown , Valerio Passini , linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH] ACPI / hotplug / PCI: Allocate resources directly under the non-hotplug bridge Date: Wed, 06 Nov 2019 13:28:27 +0100 Message-ID: <4228135.D2MuoWt6n7@kreacher> In-Reply-To: <20191030150545.19885-1-mika.westerberg@linux.intel.com> References: <20191030150545.19885-1-mika.westerberg@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Wednesday, October 30, 2019 4:05:45 PM CET Mika Westerberg wrote: > Valerio and others reported that commit 84c8b58ed3ad ("ACPI / hotplug / > PCI: Don't scan bridges managed by native hotplug") prevents some recent > LG and HP laptops from booting with endless loop of: > > [ 26.237796] ACPI Error: No handler or method for GPE 08, disabling event (20190215/evgpe-835) > [ 26.238699] ACPI Error: No handler or method for GPE 09, disabling event (20190215/evgpe-835) > [ 26.239306] ACPI Error: No handler or method for GPE 0A, disabling event (20190215/evgpe-835) > ... > > What seems to happen is that during boot, after the initial PCI > enumeration when EC is enabled the platform triggers ACPI Notify() to > one of the root ports. The root port itself looks like this: > > [ 0.723757] pci 0000:00:1b.0: PCI bridge to [bus 02-3a] > [ 0.723765] pci 0000:00:1b.0: bridge window [mem 0xc4000000-0xda0fffff] > [ 0.723773] pci 0000:00:1b.0: bridge window [mem 0x80000000-0xa1ffffff 64bit pref] > > The BIOS has configured the root port so that it does not have I/O > bridge window. > > Now when the ACPI Notify() is triggered ACPI hotplug handler calls > acpiphp_native_scan_bridge() for each non-hotplug bridge (as this system > is using native PCIe hotplug) and pci_assign_unassigned_bridge_resources() > to allocate resources. > > The device connected to the root port is a PCIe switch (Thunderbolt > controller) with two hotplug downstream ports. Because of the hotplug > ports __pci_bus_size_bridges() tries to add "additional I/O" of 256 > bytes to each (DEFAULT_HOTPLUG_IO_SIZE). This gets further aligned to 4k > as that's the minimum I/O window size so each hotplug port gets 4k I/O > window and the same happens for the root port (which is also hotplug > port). This means 3 * 4k = 12k I/O window. > > Because of this pci_assign_unassigned_bridge_resources() ends up opening > a I/O bridge window for the root port at first available I/O address > which seems to be in range 0x1000 - 0x3fff. Normally this range is used > for ACPI stuff such as GPE bits (below is part of /proc/ioports): > > 1800-1803 : ACPI PM1a_EVT_BLK > 1804-1805 : ACPI PM1a_CNT_BLK > 1808-180b : ACPI PM_TMR > 1810-1815 : ACPI CPU throttle > 1850-1850 : ACPI PM2_CNT_BLK > 1854-1857 : pnp 00:05 > 1860-187f : ACPI GPE0_BLK > > However, when the ACPI Notify() happened this range was not yet reserved > for ACPI/PNP (that happens later) so PCI gets it. It then starts writing > to this range and accidentally stomps over GPE bits among other things > causing the endless stream of messages about missing GPE handler. > > This problem does not happen if "pci=hpiosize=0" is passed in the kernel > command line. The reason is that then the kernel does not try to > allocate the additional 256 bytes for each hotplug port. > > Fix this by allocating resources directly below the non-hotplug bridges > where a new device may appear as a result of ACPI Notify(). This avoids > the hotplug bridges and prevents opening the additional I/O window. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=203617 > Fixes: 84c8b58ed3ad ("ACPI / hotplug / PCI: Don't scan bridges managed by native hotplug") > Cc: stable@vger.kernel.org > Reported-by: Valerio Passini > Signed-off-by: Mika Westerberg That should work: Reviewed-by: Rafael J. Wysocki Bjorn, if you want me to take this, please let me know. > --- > I was able to reproduce this without access to the affected system by > forcing ACPI core to send Notify() to the TBT root port like this: > > void acpi_notify_rp(void) > { > struct acpi_device *adev; > acpi_handle handle; > > if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB.PCI0.RP17", &handle))) > return; > > if (acpi_bus_get_device(handle, &adev)) > return; > > dev_info(&adev->dev, "queueing hotplug\n"); > acpiphp_hotplug_notify(adev, ACPI_NOTIFY_BUS_CHECK); > } > > and calling it from acpi_init() directly after acpi_ec_init(). > > drivers/pci/hotplug/acpiphp_glue.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > index e4c46637f32f..b3869951c0eb 100644 > --- a/drivers/pci/hotplug/acpiphp_glue.c > +++ b/drivers/pci/hotplug/acpiphp_glue.c > @@ -449,8 +449,15 @@ static void acpiphp_native_scan_bridge(struct pci_dev *bridge) > > /* Scan non-hotplug bridges that need to be reconfigured */ > for_each_pci_bridge(dev, bus) { > - if (!hotplug_is_native(dev)) > - max = pci_scan_bridge(bus, dev, max, 1); > + if (hotplug_is_native(dev)) > + continue; > + > + max = pci_scan_bridge(bus, dev, max, 1); > + if (dev->subordinate) { > + pcibios_resource_survey_bus(dev->subordinate); > + pci_bus_size_bridges(dev->subordinate); > + pci_bus_assign_resources(dev->subordinate); > + } > } > } > > @@ -480,7 +487,6 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge) > if (PCI_SLOT(dev->devfn) == slot->device) > acpiphp_native_scan_bridge(dev); > } > - pci_assign_unassigned_bridge_resources(bus->self); > } else { > LIST_HEAD(add_list); > int max, pass; >