From patchwork Wed Jul 17 23:35:45 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rafael Wysocki X-Patchwork-Id: 2829200 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 14884C0AB2 for ; Wed, 17 Jul 2013 23:27:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3AC3A204F2 for ; Wed, 17 Jul 2013 23:27:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4875320276 for ; Wed, 17 Jul 2013 23:27:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757578Ab3GQX1Q (ORCPT ); Wed, 17 Jul 2013 19:27:16 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:47808 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757633Ab3GQX1O (ORCPT ); Wed, 17 Jul 2013 19:27:14 -0400 Received: from vostro.rjw.lan (aeqz195.neoplus.adsl.tpnet.pl [79.191.181.195]) by hydra.sisk.pl (Postfix) with ESMTPSA id 27F7FE3DCA; Thu, 18 Jul 2013 01:22:51 +0200 (CEST) From: "Rafael J. Wysocki" To: ACPI Devel Maling List Cc: Bjorn Helgaas , LKML , Linux PCI , Yinghai Lu , Jiang Liu , Mika Westerberg , "Kirill A. Shutemov" Subject: [PATCH 29/30] ACPI / hotplug / PCI: Clean up bridge_mutex usage Date: Thu, 18 Jul 2013 01:35:45 +0200 Message-ID: <1699392.oW1xlocqas@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.10.0+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <2366394.4EoP1MXmG2@vostro.rjw.lan> References: <26431283.HJCKsss0rt@vostro.rjw.lan> <3718119.FLASu5DBx8@vostro.rjw.lan> <2366394.4EoP1MXmG2@vostro.rjw.lan> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rafael J. Wysocki Do not acquire bridge_mutex around the addition of a slot to its bridge's list of slots and arount the addition of a function to its slot's list of functions, because that doesn't help anything right now (those lists are walked without any locking anyway). However, acquire bridge_mutex around the list walk in acpiphp_remove_slots() and use list_for_each_entry() there, because we terminate the walk as soon as we find the first matching entry. This prevents that list walk from colliding with bridge addition and removal. Signed-off-by: Rafael J. Wysocki --- drivers/pci/hotplug/acpiphp_glue.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c =================================================================== --- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c +++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c @@ -323,9 +323,7 @@ static acpi_status register_slot(acpi_ha INIT_LIST_HEAD(&slot->funcs); mutex_init(&slot->crit_sect); - mutex_lock(&bridge_mutex); list_add_tail(&slot->node, &bridge->slots); - mutex_unlock(&bridge_mutex); /* Register slots for ejectable funtions only. */ if (acpi_pci_check_ejectable(pbus, handle) || is_dock_device(handle)) { @@ -355,9 +353,7 @@ static acpi_status register_slot(acpi_ha slot_found: newfunc->slot = slot; - mutex_lock(&bridge_mutex); list_add_tail(&newfunc->sibling, &slot->funcs); - mutex_unlock(&bridge_mutex); if (pci_bus_read_dev_vendor_id(pbus, PCI_DEVFN(device, function), &val, 60*1000)) @@ -1025,17 +1021,21 @@ void acpiphp_enumerate_slots(struct pci_ /* Destroy hotplug slots associated with the PCI bus */ void acpiphp_remove_slots(struct pci_bus *bus) { - struct acpiphp_bridge *bridge, *tmp; + struct acpiphp_bridge *bridge; if (acpiphp_disabled) return; - list_for_each_entry_safe(bridge, tmp, &bridge_list, list) + mutex_lock(&bridge_mutex); + list_for_each_entry(bridge, &bridge_list, list) if (bridge->pci_bus == bus) { + mutex_unlock(&bridge_mutex); cleanup_bridge(bridge); put_bridge(bridge); - break; + return; } + + mutex_unlock(&bridge_mutex); } /**