From 355f1ecbcc81efb6611290b772e7ae77ece4059c Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 17 Apr 2013 15:58:23 -0700 Subject: [PATCH] thinkpad-acpi: kill hotkey_thread_mutex hotkey_kthread() does try_to_freeze() under hotkey_thread_mutex. We can simply kill this mutex, hotkey_poll_stop_sync() does not need to serialize with hotkey_kthread(). When kthread_stop() returns the thread is already dead, it called do_exit()->complete_vfork_done(). Reported-by: Artem Savkov Reported-by: Maciej Rutecki Signed-off-by: Oleg Nesterov Acked-by: Henrique de Moraes Holschuh Cc: Matthew Garrett Cc: "Rafael J. Wysocki" Reviewed-by: Mandeep Singh Baines Cc: Aaron Lu Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/platform/x86/thinkpad_acpi.c | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 9a907567f41e..edec135b1685 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -1964,9 +1964,6 @@ struct tp_nvram_state { /* kthread for the hotkey poller */ static struct task_struct *tpacpi_hotkey_task; -/* Acquired while the poller kthread is running, use to sync start/stop */ -static struct mutex hotkey_thread_mutex; - /* * Acquire mutex to write poller control variables as an * atomic block. @@ -2462,8 +2459,6 @@ static int hotkey_kthread(void *data) unsigned int poll_freq; bool was_frozen; - mutex_lock(&hotkey_thread_mutex); - if (tpacpi_lifecycle == TPACPI_LIFE_EXITING) goto exit; @@ -2523,7 +2518,6 @@ static int hotkey_kthread(void *data) } exit: - mutex_unlock(&hotkey_thread_mutex); return 0; } @@ -2533,9 +2527,6 @@ static void hotkey_poll_stop_sync(void) if (tpacpi_hotkey_task) { kthread_stop(tpacpi_hotkey_task); tpacpi_hotkey_task = NULL; - mutex_lock(&hotkey_thread_mutex); - /* at this point, the thread did exit */ - mutex_unlock(&hotkey_thread_mutex); } } @@ -3234,7 +3225,6 @@ static int __init hotkey_init(struct ibm_init_struct *iibm) mutex_init(&hotkey_mutex); #ifdef CONFIG_THINKPAD_ACPI_HOTKEY_POLL - mutex_init(&hotkey_thread_mutex); mutex_init(&hotkey_thread_data_mutex); #endif -- 2.30.2