Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | Re: Hang on suspend | Date | Sat, 23 Feb 2008 21:43:31 +0100 |
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On Thursday, 21 of February 2008, Julian Blake Kongslie wrote: > I'm getting a hang at suspend on 2.6.25-rc2. Booting with > no_console_suspend let me catch the error, which I photographed and > transcribed (hopefully without error) below. > > This is a Lenovo Thinkpad T43p. > > I've attached my config and a partial dmesg (this machine generates a > lot of messages at boot, and overfills the buffer before klogd gets to > it).
Can you please apply the appened patch and retest?
Thanks, Rafael
--- drivers/base/power/main.c | 84 ++-------------------------------------------- 1 file changed, 4 insertions(+), 80 deletions(-)
Index: linux-2.6/drivers/base/power/main.c =================================================================== --- linux-2.6.orig/drivers/base/power/main.c +++ linux-2.6/drivers/base/power/main.c @@ -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); } /** @@ -266,7 +242,7 @@ 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); @@ -275,25 +251,6 @@ static void dpm_resume(void) } /** - * 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 * * Unregister all devices on the dpm_destroy list. @@ -305,7 +262,6 @@ static void unregister_dropped_devices(v 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 +280,6 @@ void device_resume(void) { might_sleep(); dpm_resume(); - unlock_all_devices(); unregister_dropped_devices(); up_write(&pm_sleep_rwsem); } @@ -461,8 +416,8 @@ static int dpm_suspend(pm_message_t stat 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); @@ -478,7 +433,7 @@ static int dpm_suspend(pm_message_t stat "")); mutex_lock(&dpm_list_mtx); if (list_empty(&dev->power.entry)) - list_add(&dev->power.entry, &dpm_locked); + list_add_tail(&dev->power.entry, &dpm_active); break; } mutex_lock(&dpm_list_mtx); @@ -491,36 +446,6 @@ static int dpm_suspend(pm_message_t stat } /** - * 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 +458,6 @@ 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();
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