Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-23 12:42:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

PM: Do not acquire device semaphores upfront during suspend

Browse Source 
Remove the code that acquires all device semaphores from the suspend
code path as it causes multiple problems to appear (most notably,
http://bugzilla.kernel.org/show_bug.cgi?id=10030) and revert the
change introduced by commit 4145ed6dc5
depending on the code being removed.

Remove pm_sleep_lock()/pm_sleep_unlock() from device_add() to avoid
the issue reported at http://bugzilla.kernel.org/show_bug.cgi?id=9874.

It should fix the regreesions reported at:
	http://bugzilla.kernel.org/show_bug.cgi?id=9874
	http://bugzilla.kernel.org/show_bug.cgi?id=10030

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Rafael J. Wysocki 2008-02-25 00:35:04 +01:00 committed by Greg Kroah-Hartman
parent a4573c488d
commit 7a8d37a373
3 changed files with 17 additions and 99 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/base/core.c
View File

@ -770,13 +770,6 @@ int device_add(struct device *dev)
struct class_interface *class_intf;
int error;
error = pm_sleep_lock();
if (error) {
dev_warn(dev, "Suspicious %s during suspend\n", __FUNCTION__);
dump_stack();
return error;
}
dev = get_device(dev);
if (!dev || !strlen(dev->bus_id)) {
error = -EINVAL;
@ -843,7 +836,6 @@ int device_add(struct device *dev)
}
Done:
put_device(dev);
pm_sleep_unlock();
return error;
BusError:
device_pm_remove(dev);

106
drivers/base/power/main.c
View File

@ -48,7 +48,6 @@
*/
LIST_HEAD(dpm_active);
static LIST_HEAD(dpm_locked);
static LIST_HEAD(dpm_off);
static LIST_HEAD(dpm_off_irq);
static LIST_HEAD(dpm_destroy);
@ -81,28 +80,6 @@ void device_pm_add(struct device *dev)
*/
void device_pm_remove(struct device *dev)
{
/*
* If this function is called during a suspend, it will be blocked,
* because we're holding the device's semaphore at that time, which may
* lead to a deadlock. In that case we want to print a warning.
* However, it may also be called by unregister_dropped_devices() with
* the device's semaphore released, in which case the warning should
* not be printed.
*/
if (down_trylock(&dev->sem)) {
if (down_read_trylock(&pm_sleep_rwsem)) {
/* No suspend in progress, wait on dev->sem */
down(&dev->sem);
up_read(&pm_sleep_rwsem);
} else {
/* Suspend in progress, we may deadlock */
dev_warn(dev, "Suspicious %s during suspend\n",
__FUNCTION__);
dump_stack();
/* The user has been warned ... */
down(&dev->sem);
}
}
pr_debug("PM: Removing info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus",
kobject_name(&dev->kobj));
@ -110,7 +87,6 @@ void device_pm_remove(struct device *dev)
dpm_sysfs_remove(dev);
list_del_init(&dev->power.entry);
mutex_unlock(&dpm_list_mtx);
up(&dev->sem);
}
/**
@ -230,6 +206,8 @@ static int resume_device(struct device *dev)
TRACE_DEVICE(dev);
TRACE_RESUME(0);
down(&dev->sem);
if (dev->bus && dev->bus->resume) {
dev_dbg(dev,"resuming\n");
error = dev->bus->resume(dev);
@ -245,6 +223,8 @@ static int resume_device(struct device *dev)
error = dev->class->resume(dev);
}
up(&dev->sem);
TRACE_RESUME(error);
return error;
}
@ -266,7 +246,7 @@ static void dpm_resume(void)
struct list_head *entry = dpm_off.next;
struct device *dev = to_device(entry);
list_move_tail(entry, &dpm_locked);
list_move_tail(entry, &dpm_active);
mutex_unlock(&dpm_list_mtx);
resume_device(dev);
mutex_lock(&dpm_list_mtx);
@ -274,25 +254,6 @@ static void dpm_resume(void)
mutex_unlock(&dpm_list_mtx);
}
/**
* unlock_all_devices - Release each device's semaphore
*
* Go through the dpm_off list. Put each device on the dpm_active
* list and unlock it.
*/
static void unlock_all_devices(void)
{
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_locked)) {
struct list_head *entry = dpm_locked.prev;
struct device *dev = to_device(entry);
list_move(entry, &dpm_active);
up(&dev->sem);
}
mutex_unlock(&dpm_list_mtx);
}
/**
* unregister_dropped_devices - Unregister devices scheduled for removal
*
@ -305,7 +266,6 @@ static void unregister_dropped_devices(void)
struct list_head *entry = dpm_destroy.next;
struct device *dev = to_device(entry);
up(&dev->sem);
mutex_unlock(&dpm_list_mtx);
/* This also removes the device from the list */
device_unregister(dev);
@ -324,7 +284,6 @@ void device_resume(void)
{
might_sleep();
dpm_resume();
unlock_all_devices();
unregister_dropped_devices();
up_write(&pm_sleep_rwsem);
}
@ -388,18 +347,15 @@ int device_power_down(pm_message_t state)
struct list_head *entry = dpm_off.prev;
struct device *dev = to_device(entry);
list_del_init(&dev->power.entry);
error = suspend_device_late(dev, state);
if (error) {
printk(KERN_ERR "Could not power down device %s: "
"error %d\n",
kobject_name(&dev->kobj), error);
if (list_empty(&dev->power.entry))
list_add(&dev->power.entry, &dpm_off);
break;
}
if (list_empty(&dev->power.entry))
list_add(&dev->power.entry, &dpm_off_irq);
if (!list_empty(&dev->power.entry))
list_move(&dev->power.entry, &dpm_off_irq);
}
if (!error)
@ -419,6 +375,8 @@ static int suspend_device(struct device *dev, pm_message_t state)
{
int error = 0;
down(&dev->sem);
if (dev->power.power_state.event) {
dev_dbg(dev, "PM: suspend %d-->%d\n",
dev->power.power_state.event, state.event);
@ -441,6 +399,9 @@ static int suspend_device(struct device *dev, pm_message_t state)
error = dev->bus->suspend(dev, state);
suspend_report_result(dev->bus->suspend, error);
}
up(&dev->sem);
return error;
}
@ -461,11 +422,10 @@ static int dpm_suspend(pm_message_t state)
int error = 0;
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_locked)) {
struct list_head *entry = dpm_locked.prev;
while (!list_empty(&dpm_active)) {
struct list_head *entry = dpm_active.prev;
struct device *dev = to_device(entry);
list_del_init(&dev->power.entry);
mutex_unlock(&dpm_list_mtx);
error = suspend_device(dev, state);
if (error) {
@ -476,50 +436,17 @@ static int dpm_suspend(pm_message_t state)
(error == -EAGAIN ?
" (please convert to suspend_late)" :
""));
mutex_lock(&dpm_list_mtx);
if (list_empty(&dev->power.entry))
list_add(&dev->power.entry, &dpm_locked);
break;
}
mutex_lock(&dpm_list_mtx);
if (list_empty(&dev->power.entry))
list_add(&dev->power.entry, &dpm_off);
if (!list_empty(&dev->power.entry))
list_move(&dev->power.entry, &dpm_off);
}
mutex_unlock(&dpm_list_mtx);
return error;
}
/**
* lock_all_devices - Acquire every device's semaphore
*
* Go through the dpm_active list. Carefully lock each device's
* semaphore and put it in on the dpm_locked list.
*/
static void lock_all_devices(void)
{
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_active)) {
struct list_head *entry = dpm_active.next;
struct device *dev = to_device(entry);
/* Required locking order is dev->sem first,
* then dpm_list_mutex. Hence this awkward code.
*/
get_device(dev);
mutex_unlock(&dpm_list_mtx);
down(&dev->sem);
mutex_lock(&dpm_list_mtx);
if (list_empty(entry))
up(&dev->sem); /* Device was removed */
else
list_move_tail(entry, &dpm_locked);
put_device(dev);
}
mutex_unlock(&dpm_list_mtx);
}
/**
* device_suspend - Save state and stop all devices in system.
* @state: new power management state
@ -533,7 +460,6 @@ int device_suspend(pm_message_t state)
might_sleep();
down_write(&pm_sleep_rwsem);
lock_all_devices();
error = dpm_suspend(state);
if (error)
device_resume();

2
drivers/usb/core/usb.c
View File

@ -233,7 +233,7 @@ static int ksuspend_usb_init(void)
* singlethreaded. Its job doesn't justify running on more
* than one CPU.
*/
ksuspend_usb_wq = create_singlethread_workqueue("ksuspend_usbd");
ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd");
if (!ksuspend_usb_wq)
return -ENOMEM;
return 0;