From 9090589d87506c578ea1523ffd7ae7fd9424fb28 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Tue, 7 Apr 2009 10:24:29 +0800 Subject: ACPI: convert acpi_device_lock spinlock to mutex Convert acpi_device_lock to a mutex to avoid a potential race upon access to /proc/acpi/wakeup Delete the lock entirely in wakeup.c since it is not necessary (and can not sleep) Found-by: Linus Torvalds Signed-off-by: Shaohua Li Signed-off-by: Len Brown --- drivers/acpi/wakeup.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) (limited to 'drivers/acpi/wakeup.c') diff --git a/drivers/acpi/wakeup.c b/drivers/acpi/wakeup.c index 5aee8c26cc9f..88725dcdf8bc 100644 --- a/drivers/acpi/wakeup.c +++ b/drivers/acpi/wakeup.c @@ -12,12 +12,14 @@ #include "internal.h" #include "sleep.h" +/* + * We didn't lock acpi_device_lock in the file, because it invokes oops in + * suspend/resume and isn't really required as this is called in S-state. At + * that time, there is no device hotplug + **/ #define _COMPONENT ACPI_SYSTEM_COMPONENT ACPI_MODULE_NAME("wakeup_devices") -extern struct list_head acpi_wakeup_device_list; -extern spinlock_t acpi_device_lock; - /** * acpi_enable_wakeup_device_prep - prepare wakeup devices * @sleep_state: ACPI state @@ -29,7 +31,6 @@ void acpi_enable_wakeup_device_prep(u8 sleep_state) { struct list_head *node, *next; - spin_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, @@ -40,11 +41,8 @@ void acpi_enable_wakeup_device_prep(u8 sleep_state) (sleep_state > (u32) dev->wakeup.sleep_state)) continue; - spin_unlock(&acpi_device_lock); acpi_enable_wakeup_device_power(dev, sleep_state); - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); } /** @@ -60,7 +58,6 @@ void acpi_enable_wakeup_device(u8 sleep_state) * Caution: this routine must be invoked when interrupt is disabled * Refer ACPI2.0: P212 */ - spin_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, wakeup_list); @@ -74,22 +71,17 @@ void acpi_enable_wakeup_device(u8 sleep_state) if ((!dev->wakeup.state.enabled && !dev->wakeup.flags.prepared) || sleep_state > (u32) dev->wakeup.sleep_state) { if (dev->wakeup.flags.run_wake) { - spin_unlock(&acpi_device_lock); /* set_gpe_type will disable GPE, leave it like that */ acpi_set_gpe_type(dev->wakeup.gpe_device, dev->wakeup.gpe_number, ACPI_GPE_TYPE_RUNTIME); - spin_lock(&acpi_device_lock); } continue; } - spin_unlock(&acpi_device_lock); if (!dev->wakeup.flags.run_wake) acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number); - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); } /** @@ -101,7 +93,6 @@ void acpi_disable_wakeup_device(u8 sleep_state) { struct list_head *node, *next; - spin_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, wakeup_list); @@ -112,19 +103,16 @@ void acpi_disable_wakeup_device(u8 sleep_state) if ((!dev->wakeup.state.enabled && !dev->wakeup.flags.prepared) || sleep_state > (u32) dev->wakeup.sleep_state) { if (dev->wakeup.flags.run_wake) { - spin_unlock(&acpi_device_lock); acpi_set_gpe_type(dev->wakeup.gpe_device, dev->wakeup.gpe_number, ACPI_GPE_TYPE_WAKE_RUN); /* Re-enable it, since set_gpe_type will disable it */ acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number); - spin_lock(&acpi_device_lock); } continue; } - spin_unlock(&acpi_device_lock); acpi_disable_wakeup_device_power(dev); /* Never disable run-wake GPE */ if (!dev->wakeup.flags.run_wake) { @@ -133,16 +121,14 @@ void acpi_disable_wakeup_device(u8 sleep_state) acpi_clear_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number, ACPI_NOT_ISR); } - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); } int __init acpi_wakeup_device_init(void) { struct list_head *node, *next; - spin_lock(&acpi_device_lock); + mutex_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, @@ -150,15 +136,13 @@ int __init acpi_wakeup_device_init(void) /* In case user doesn't load button driver */ if (!dev->wakeup.flags.run_wake || dev->wakeup.state.enabled) continue; - spin_unlock(&acpi_device_lock); acpi_set_gpe_type(dev->wakeup.gpe_device, dev->wakeup.gpe_number, ACPI_GPE_TYPE_WAKE_RUN); acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number); dev->wakeup.state.enabled = 1; - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); + mutex_unlock(&acpi_device_lock); return 0; } -- cgit v1.2.3