From patchwork Wed Sep 19 11:32:47 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Westerberg X-Patchwork-Id: 971570 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42Fd5L6LKZz9sB5 for ; Wed, 19 Sep 2018 21:32:54 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731493AbeISRKW (ORCPT ); Wed, 19 Sep 2018 13:10:22 -0400 Received: from mga03.intel.com ([134.134.136.65]:61770 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731247AbeISRKW (ORCPT ); Wed, 19 Sep 2018 13:10:22 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Sep 2018 04:32:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,393,1531810800"; d="scan'208";a="75568077" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga006.jf.intel.com with ESMTP; 19 Sep 2018 04:32:48 -0700 Received: by black.fi.intel.com (Postfix, from userid 1001) id 6B4A8162; Wed, 19 Sep 2018 14:32:47 +0300 (EEST) From: Mika Westerberg To: "Rafael J. Wysocki" , Bjorn Helgaas Cc: Len Brown , Peter Anemone , Mika Westerberg , linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH] ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge Date: Wed, 19 Sep 2018 14:32:47 +0300 Message-Id: <20180919113247.4274-1-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 2.18.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org HP 6730b laptop has an ethernet NIC connected to one of the PCIe root ports. The root ports itself are native PCIe hotplug capable. Now, during boot after PCI devices are scanned the BIOS triggers ACPI bus check directly to the NIC: [ 0.942239] ACPI: \_SB_.PCI0.RP06.NIC_: Bus check in hotplug_event() It is not clear why it is sending bus check but regardless the ACPI hotplug notify handler calls enable_slot() directly (instead of going through acpiphp_check_bridge() as there is no bridge) which ends up handling special case for non-hotplug bridges with native PCIe hotplug. This results a crash of some kind but the reporter only sees black screen so it is hard to figure out the exact spot and what actually happens. Based on few fix proposals it was tracked to crash somewhere inside pci_assign_unassigned_bridge_resources(). In any case we should not really be in that special branch at all because the ACPI notify happened to a slot that is not a PCI bridge (it is just a regular PCI device). Fix this so that we only go to that special branch if we are calling enable_slot() for a bridge (e.g the ACPI notification was for the bridge). Link: https://bugzilla.kernel.org/show_bug.cgi?id=201127 Fixes: 84c8b58ed3ad ACPI / hotplug / PCI: Don't scan bridges managed by native hotplug Reported-by: Peter Anemone Signed-off-by: Mika Westerberg --- drivers/pci/hotplug/acpiphp_glue.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index ef0b1b6ba86f..fa2d82ae6ccd 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -457,17 +457,20 @@ static void acpiphp_native_scan_bridge(struct pci_dev *bridge) /** * enable_slot - enable, configure a slot * @slot: slot to be enabled + * @bridge: Bridge if the hotplug was directly to the bridge. %NULL + * otherwise. * * This function should be called per *physical slot*, * not per each slot object in ACPI namespace. */ -static void enable_slot(struct acpiphp_slot *slot) +static void enable_slot(struct acpiphp_slot *slot, + const struct acpiphp_bridge *bridge) { struct pci_dev *dev; struct pci_bus *bus = slot->bus; struct acpiphp_func *func; - if (bus->self && hotplug_is_native(bus->self)) { + if (bridge && bus->self && hotplug_is_native(bus->self)) { /* * If native hotplug is used, it will take care of hotplug * slot management and resource allocation for hotplug @@ -701,7 +704,7 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge) trim_stale_devices(dev); /* configure all functions */ - enable_slot(slot); + enable_slot(slot, bridge); } else { disable_slot(slot); } @@ -785,7 +788,7 @@ static void hotplug_event(u32 type, struct acpiphp_context *context) if (bridge) acpiphp_check_bridge(bridge); else if (!(slot->flags & SLOT_IS_GOING_AWAY)) - enable_slot(slot); + enable_slot(slot, NULL); break; @@ -973,7 +976,7 @@ int acpiphp_enable_slot(struct acpiphp_slot *slot) /* configure all functions */ if (!(slot->flags & SLOT_ENABLED)) - enable_slot(slot); + enable_slot(slot, NULL); pci_unlock_rescan_remove(); return 0;