Rafael, this patch is in the acpica.git tree as 7a3bd2d ("Dispatcher: Update thread ID for recursive method calls"). I've had many positive testing results from hardware vendors and users with this patch and this resolves many of the problems seen here: https://bugzilla.kernel.org/show_bug.cgi?id=115121 This does not fix the problems with the TB docking station. Although this patch will also be required, the docking station issues require a FW update. Updated FW should be coming soon to resolve those problems. P. ----8<---- The following hung task trace is seen when hotplugging an ethernet dongle in a Thunderbolt port on Linux. INFO: task kworker/0:4:1468 blocked for more than 120 seconds. Tainted: G W 4.6.0-rc1+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:4 D ffff8802a265ba38 13344 1468 2 0x00000000 Workqueue: kacpid acpi_os_execute_deferred ffff8802a265ba38 ffff8802a265ba00 ffffffff81130200 ffffffff81e0d580 ffff88029e5eb340 ffff8802a265c000 ffff88029d69d000 ffff88029e5eb340 ffffffff818c1b8d ffff8802b64e8758 ffff8802a265ba50 ffffffff818bdfcc Call Trace: [<ffffffff81130200>] ? test_callback+0x10/0x30 [<ffffffff818c1b8d>] ? __down_timeout+0x5d/0xd0 [<ffffffff818bdfcc>] schedule+0x3c/0x90 [<ffffffff818c2d60>] schedule_timeout+0x210/0x360 [<ffffffff8103fc89>] ? sched_clock+0x9/0x10 [<ffffffff810ee51c>] ? local_clock+0x1c/0x20 [<ffffffff81110c16>] ? mark_held_locks+0x76/0xa0 [<ffffffff818c3cfc>] ? _raw_spin_unlock_irq+0x2c/0x40 [<ffffffff818c1b8d>] ? __down_timeout+0x5d/0xd0 [<ffffffff81110d35>] ? trace_hardirqs_on_caller+0xf5/0x1b0 [<ffffffff818c1b8d>] ? __down_timeout+0x5d/0xd0 [<ffffffff818c1bac>] __down_timeout+0x7c/0xd0 [<ffffffff818c44b2>] ? _raw_spin_lock_irqsave+0x82/0x90 [<ffffffff8110b87c>] down_timeout+0x4c/0x60 [<ffffffff814e3a9c>] acpi_os_wait_semaphore+0xaa/0x16a [<ffffffff81510f37>] acpi_ex_system_wait_mutex+0x81/0xfa [<ffffffff814f8796>] acpi_ds_begin_method_execution+0x25a/0x373 [<ffffffff814f8cea>] acpi_ds_call_control_method+0x107/0x2e0 [<ffffffff8151ed60>] acpi_ps_parse_aml+0x177/0x495 [<ffffffff8151fa46>] acpi_ps_execute_method+0x1f7/0x2b9 [<ffffffff81516c9a>] acpi_ns_evaluate+0x2ee/0x435 [<ffffffff814ff84a>] acpi_ev_asynch_execute_gpe_method+0xbd/0x159 [<ffffffff814e2a69>] acpi_os_execute_deferred+0x17/0x23 [<ffffffff810d1fc2>] process_one_work+0x242/0x700 [<ffffffff810d1f3a>] ? process_one_work+0x1ba/0x700 [<ffffffff810d24ce>] worker_thread+0x4e/0x490 [<ffffffff810d2480>] ? process_one_work+0x700/0x700 [<ffffffff810d2480>] ? process_one_work+0x700/0x700 [<ffffffff810d98b1>] kthread+0x101/0x120 [<ffffffff81110d35>] ? trace_hardirqs_on_caller+0xf5/0x1b0 [<ffffffff818c4832>] ret_from_fork+0x22/0x50 [<ffffffff810d97b0>] ? kthread_create_on_node+0x250/0x250 2 locks held by kworker/0:4/1468: #0: ("kacpid"){.+.+.+}, at: [<ffffffff810d1f3a>] process_one_work+0x1ba/0x700 #1: ((&dpc->work)){+.+.+.}, at: [<ffffffff810d1f3a>] process_one_work+0x1ba/0x700 The issue appears to be that the kworker thread attempts to acquire the _E42 method's mutex twice when executing acpi_ps_execute_method() and recursing through the entry method. The current code does take the possiblity of this recursion into account, however, it is only for the case where the walk_state has been populated. This can be fixed by setting the thread id in the !walk_state case to allow for recursion. Cc: Robert Moore <robert.moore@xxxxxxxxx> Cc: Lv Zheng <lv.zheng@xxxxxxxxx> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> Cc: Len Brown <lenb@xxxxxxxxxx> Cc: linux-acpi@xxxxxxxxxxxxxxx Cc: Mario_Limonciello@xxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Cc: devel@xxxxxxxxxx Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx> --- drivers/acpi/acpica/dsmethod.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/acpi/acpica/dsmethod.c b/drivers/acpi/acpica/dsmethod.c index 1982310..93799db 100644 --- a/drivers/acpi/acpica/dsmethod.c +++ b/drivers/acpi/acpica/dsmethod.c @@ -428,6 +428,9 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node, obj_desc->method.mutex->mutex. original_sync_level = obj_desc->method.mutex->mutex.sync_level; + + obj_desc->method.mutex->mutex.thread_id = + acpi_os_get_thread_id(); } } -- 1.7.9.3 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html