Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754657Ab3FKPBJ (ORCPT ); Tue, 11 Jun 2013 11:01:09 -0400 Received: from mail-pb0-f47.google.com ([209.85.160.47]:35921 "EHLO mail-pb0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753803Ab3FKPBH (ORCPT ); Tue, 11 Jun 2013 11:01:07 -0400 Message-ID: <51B73BAB.3030406@gmail.com> Date: Tue, 11 Jun 2013 23:00:59 +0800 From: Jiang Liu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130404 Thunderbird/17.0.5 MIME-Version: 1.0 To: "Alexander E. Patrakov" CC: Jiang Liu , Bjorn Helgaas , Yinghai Lu , "Rafael J. Wysocki" , linux-pci@vger.kernel.org, "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] ACPIPHP: fix device destroying order issue in handling dock notification References: <1370951543-15841-1-git-send-email-jiang.liu@huawei.com> <51B7170E.2060608@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8025 Lines: 189 Hi Alexander, This is much more harder issue to resolve. Let's first work around this issue and check whether other things are OK. The patch below is just a prove of concept, could you please help to try it? Regards! Gerry --- diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c index a7ba608..dde1cec 100644 --- a/drivers/acpi/dock.c +++ b/drivers/acpi/dock.c @@ -121,9 +121,7 @@ static void dock_add_hotplug_device(struct dock_station *ds, struct dock_dependent_device *dd) { - mutex_lock(&ds->hp_lock); list_add_tail(&dd->hotplug_list, &ds->hotplug_devices); - mutex_unlock(&ds->hp_lock); } /** @@ -137,9 +135,7 @@ static void dock_del_hotplug_device(struct dock_station *ds, struct dock_dependent_device *dd) { - mutex_lock(&ds->hp_lock); list_del_init(&dd->hotplug_list); - mutex_unlock(&ds->hp_lock); } /** --- On Tue 11 Jun 2013 09:38:59 PM CST, Alexander E. Patrakov wrote: > 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. 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