From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f50.google.com ([209.85.215.50]:52615 "EHLO mail-la0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750974Ab3FKNjB (ORCPT ); Tue, 11 Jun 2013 09:39:01 -0400 MIME-Version: 1.0 In-Reply-To: <51B7170E.2060608@gmail.com> References: <1370951543-15841-1-git-send-email-jiang.liu@huawei.com> <51B7170E.2060608@gmail.com> Date: Tue, 11 Jun 2013 19:38:59 +0600 Message-ID: Subject: Re: [PATCH] ACPIPHP: fix device destroying order issue in handling dock notification From: "Alexander E. Patrakov" To: Jiang Liu Cc: Jiang Liu , Bjorn Helgaas , Yinghai Lu , "Rafael J. Wysocki" , linux-pci@vger.kernel.org, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-pci-owner@vger.kernel.org List-ID: 2013/6/11 Jiang Liu : > Hi Alexander, > Sorry for the deadlock, I have no machine for testing:( > Below patch should fix the deadlock issue. There is another deadlock: [ 34.316382] acpiphp_glue: found ACPI PCI Hotplug slot 1 at PCI 0000:0a:00 [ 34.316557] acpiphp: Slot [1-1] registered [ 34.316569] ============================================= [ 34.316570] [ INFO: possible recursive locking detected ] [ 34.316573] 3.10.0-rc4 #6 Tainted: G C [ 34.316575] --------------------------------------------- [ 34.316577] kworker/0:0/4 is trying to acquire lock: [ 34.316579] (&dock_station->hp_lock){+.+.+.}, at: [] register_hotplug_dock_device+0x6a/0xbf [ 34.316588] but task is already holding lock: [ 34.316590] (&dock_station->hp_lock){+.+.+.}, at: [] hotplug_dock_devices+0x2c/0xda [ 34.316595] other info that might help us debug this: [ 34.316597] Possible unsafe locking scenario: [ 34.316599] CPU0 [ 34.316601] ---- [ 34.316602] lock(&dock_station->hp_lock); [ 34.316605] lock(&dock_station->hp_lock); [ 34.316608] *** DEADLOCK *** [ 34.316611] May be due to missing lock nesting notation [ 34.316613] 5 locks held by kworker/0:0/4: [ 34.316615] #0: (kacpi_hotplug){.+.+.+}, at: [] process_one_work+0x157/0x560 [ 34.316624] #1: ((&dpc->work)#3){+.+.+.}, at: [] process_one_work+0x157/0x560 [ 34.316631] #2: (acpi_scan_lock){+.+.+.}, at: [] acpi_scan_lock_acquire+0x12/0x14 [ 34.316639] #3: (&dock_station->hp_lock){+.+.+.}, at: [] hotplug_dock_devices+0x2c/0xda [ 34.316646] #4: (&slot->crit_sect){+.+.+.}, at: [] acpiphp_enable_slot+0x1e/0x140 [ 34.316653] stack backtrace: [ 34.316657] CPU: 0 PID: 4 Comm: kworker/0:0 Tainted: G C 3.10.0-rc4 #6 [ 34.316659] Hardware name: Sony Corporation VPCZ23A4R/VAIO, BIOS R1013H5 05/21/2012 [ 34.316663] Workqueue: kacpi_hotplug acpi_os_execute_deferred [ 34.316665] ffff8802540adf40 ffff8802540d3628 ffffffff8165aaf8 ffff8802540d3718 [ 34.316670] ffffffff8109fe92 ffff8802540adf40 ffffffff8261c8a0 ffff8802540ae700 [ 34.316675] 0000000000000000 ffff8802540d3748 000000000001f180 ffff8802000000dc [ 34.316680] Call Trace: [ 34.316685] [] dump_stack+0x19/0x1b [ 34.316689] [] __lock_acquire+0x1522/0x1ee0 [ 34.316693] [] ? mark_held_locks+0x61/0x150 [ 34.316697] [] ? _raw_spin_unlock_irqrestore+0x65/0x80 [ 34.316702] [] ? acpi_ns_get_node+0xb2/0xc2 [ 34.316705] [] ? register_hotplug_dock_device+0x6a/0xbf [ 34.316709] [] lock_acquire+0x87/0x150 [ 34.316712] [] ? register_hotplug_dock_device+0x6a/0xbf [ 34.316715] [] ? register_hotplug_dock_device+0x6a/0xbf [ 34.316720] [] mutex_lock_nested+0x5e/0x3e0 [ 34.316723] [] ? register_hotplug_dock_device+0x6a/0xbf [ 34.316726] [] ? _raw_spin_unlock+0x30/0x60 [ 34.316729] [] register_hotplug_dock_device+0x6a/0xbf [ 34.316733] [] register_slot+0x467/0x5b0 [ 34.316738] [] acpi_ns_walk_namespace+0xbb/0x17b [ 34.316741] [] ? acpi_os_wait_semaphore+0x3f/0x55 [ 34.316744] [] ? free_bridge+0x100/0x100 [ 34.316748] [] ? free_bridge+0x100/0x100 [ 34.316752] [] acpi_walk_namespace+0x8e/0xc8 [ 34.316755] [] acpiphp_enumerate_slots+0x1bd/0x320 [ 34.316760] [] ? pm_runtime_init+0x106/0x110 [ 34.316764] [] acpi_pci_add_bus+0x2f/0x40 [ 34.316768] [] pcibios_add_bus+0x9/0x10 [ 34.316772] [] pci_add_new_bus+0x1c8/0x390 [ 34.316777] [] pci_scan_bridge+0x5e5/0x620 [ 34.316781] [] enable_device+0x169/0x450 [ 34.316785] [] acpiphp_enable_slot+0xca/0x140 [ 34.316789] [] __handle_hotplug_event_func+0x96/0x1a0 [ 34.316792] [] hotplug_dock_devices+0x57/0xda [ 34.316796] [] acpi_dock_deferred_cb+0xd4/0x1c8 [ 34.316799] [] acpi_os_execute_deferred+0x20/0x2d [ 34.316803] [] process_one_work+0x1c2/0x560 [ 34.316807] [] ? process_one_work+0x157/0x560 [ 34.316810] [] worker_thread+0x116/0x370 [ 34.316813] [] ? manage_workers.isra.20+0x2d0/0x2d0 [ 34.316818] [] kthread+0xd6/0xe0 [ 34.316821] [] ? _raw_spin_unlock_irq+0x2b/0x60 [ 34.316826] [] ? __init_kthread_worker+0x70/0x70 [ 34.316830] [] ret_from_fork+0x7c/0xb0 [ 34.316834] [] ? __init_kthread_worker+0x70/0x70 > Regards! > > ---- > diff --git a/drivers/pci/hotplug/acpiphp_glue.c > b/drivers/pci/hotplug/acpiphp_glue.c > index 0302645..699b8ca 100644 > --- a/drivers/pci/hotplug/acpiphp_glue.c > +++ b/drivers/pci/hotplug/acpiphp_glue.c > @@ -1075,8 +1075,6 @@ static void > _handle_hotplug_event_func(acpi_handle handle, u32 type, > struct acpi_buffer buffer = { .length = sizeof(objname), > .pointer = objname }; > > - acpi_scan_lock_acquire(); > - > acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); > > switch (type) { > @@ -1108,8 +1106,6 @@ static void > _handle_hotplug_event_func(acpi_handle handle, u32 type, > warn("notify_handler: unknown event type 0x%x for > %s\n", type, objname); > break; > } > - > - acpi_scan_lock_release(); > } > > static void _handle_hotplug_event_cb(struct work_struct *work) > @@ -1119,8 +1115,10 @@ static void _handle_hotplug_event_cb(struct > work_struct *work) > > hp_work = container_of(work, struct acpi_hp_work, work); > func = (struct acpiphp_func *)hp_work->context; > + acpi_scan_lock_acquire(); > _handle_hotplug_event_func(hp_work->handle, hp_work->type, > hp_work->context); > + acpi_scan_lock_release(); > kfree(hp_work); /* allocated in handle_hotplug_event_func */ > put_bridge(func->slot->bridge); > } > -- Alexander E. Patrakov