From patchwork Wed Oct 31 07:27:50 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: tangchen X-Patchwork-Id: 1676251 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 5F35E3FD2B for ; Wed, 31 Oct 2012 07:30:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934980Ab2JaH3Q (ORCPT ); Wed, 31 Oct 2012 03:29:16 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:25421 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S933338Ab2JaH3I (ORCPT ); Wed, 31 Oct 2012 03:29:08 -0400 X-IronPort-AV: E=Sophos;i="4.80,687,1344182400"; d="scan'208";a="6106807" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 31 Oct 2012 15:27:29 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id q9V7T2Z1013098; Wed, 31 Oct 2012 15:29:03 +0800 Received: from tangchen.fnst.cn.fujitsu.com ([10.167.225.117]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012103115281991-873970 ; Wed, 31 Oct 2012 15:28:19 +0800 From: Tang Chen To: yinghai@kernel.org, bhelgaas@google.com, lenb@kernel.org, jiang.liu@huawei.com, izumi.taku@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/3] Use kacpi_hotplug_wq to handle container hotplug event. Date: Wed, 31 Oct 2012 15:27:50 +0800 Message-Id: <1351668471-31436-3-git-send-email-tangchen@cn.fujitsu.com> X-Mailer: git-send-email 1.7.10.1 In-Reply-To: <1351668471-31436-1-git-send-email-tangchen@cn.fujitsu.com> References: <1351668471-31436-1-git-send-email-tangchen@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/10/31 15:28:20, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/10/31 15:28:20, Serialize complete at 2012/10/31 15:28:20 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org As the comments in __acpi_os_execute() said: We can't run hotplug code in keventd_wq/kacpid_wq/kacpid_notify_wq because the hotplug code may call driver .remove() functions, which invoke flush_scheduled_work/acpi_os_wait_events_complete to flush these workqueues. we should keep the hotplug code in kacpi_hotplug_wq. But we have the following call series in kernel now: acpi_ev_queue_notify_request() |--> acpi_os_execute() |--> __acpi_os_execute(type, function, context, 0) The last parameter 0 makes the container_notify_cb() executed in kacpi_notify_wq or kacpid_wq. So, we need to put the real hotplug code into kacpi_hotplug_wq. Signed-off-by: Tang Chen --- drivers/acpi/container.c | 34 ++++++++++++++++++++++++++++++---- 1 files changed, 30 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c index 69e2d6b..a10eee6 100644 --- a/drivers/acpi/container.c +++ b/drivers/acpi/container.c @@ -35,6 +35,7 @@ #include #include #include +#include #define PREFIX "ACPI: " @@ -165,14 +166,22 @@ static int container_device_add(struct acpi_device **device, acpi_handle handle) return result; } -static void container_notify_cb(acpi_handle handle, u32 type, void *context) +/* This function is of type acpi_osd_exec_callback */ +static void _container_notify_cb(void *context) { struct acpi_device *device = NULL; int result; int present; acpi_status status; + struct acpi_hp_cb_data *cb_data; + acpi_handle handle; + u32 type; u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ + cb_data = (struct acpi_hp_cb_data *)context; + handle = cb_data->handle; + type = cb_data->type; + switch (type) { case ACPI_NOTIFY_BUS_CHECK: /* Fall through */ @@ -188,7 +197,7 @@ static void container_notify_cb(acpi_handle handle, u32 type, void *context) /* device exist and this is a remove request */ device->flags.eject_pending = 1; kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE); - return; + goto out; } break; } @@ -210,20 +219,37 @@ static void container_notify_cb(acpi_handle handle, u32 type, void *context) if (!acpi_bus_get_device(handle, &device) && device) { device->flags.eject_pending = 1; kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE); - return; + goto out; } break; default: /* non-hotplug event; possibly handled by other handler */ - return; + goto out; } /* Inform firmware that the hotplug operation has completed */ (void) acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL); + +out: + kfree(context); /* allocated in container_notify_cb */ return; } +static void container_notify_cb(acpi_handle handle, u32 type, + void *context) +{ + /* + * Currently the code adds all hotplug events to the kacpid_wq + * queue when it should add hotplug events to the kacpi_hotplug_wq. + * The proper way to fix this is to reorganize the code so that + * drivers (dock, etc.) do not call acpi_os_execute(), etc. + * For now just re-add this work to the kacpi_hotplug_wq so we + * don't deadlock on hotplug actions. + */ + acpi_hp_cb_execute(handle, type, context, _container_notify_cb); +} + static acpi_status container_walk_namespace_cb(acpi_handle handle, u32 lvl, void *context, void **rv)