diff options
Diffstat (limited to 'drivers/base/power')
-rw-r--r-- | drivers/base/power/main.c | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 134a8af51511..0e99a760aebd 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -273,10 +273,38 @@ static void dpm_wait_for_suppliers(struct device *dev, bool async) device_links_read_unlock(idx); } -static void dpm_wait_for_superior(struct device *dev, bool async) +static bool dpm_wait_for_superior(struct device *dev, bool async) { - dpm_wait(dev->parent, async); + struct device *parent; + + /* + * If the device is resumed asynchronously and the parent's callback + * deletes both the device and the parent itself, the parent object may + * be freed while this function is running, so avoid that by reference + * counting the parent once more unless the device has been deleted + * already (in which case return right away). + */ + mutex_lock(&dpm_list_mtx); + + if (!device_pm_initialized(dev)) { + mutex_unlock(&dpm_list_mtx); + return false; + } + + parent = get_device(dev->parent); + + mutex_unlock(&dpm_list_mtx); + + dpm_wait(parent, async); + put_device(parent); + dpm_wait_for_suppliers(dev, async); + + /* + * If the parent's callback has deleted the device, attempting to resume + * it would be invalid, so avoid doing that then. + */ + return device_pm_initialized(dev); } static void dpm_wait_for_consumers(struct device *dev, bool async) @@ -621,7 +649,8 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn if (!dev->power.is_noirq_suspended) goto Out; - dpm_wait_for_superior(dev, async); + if (!dpm_wait_for_superior(dev, async)) + goto Out; skip_resume = dev_pm_may_skip_resume(dev); @@ -829,7 +858,8 @@ static int device_resume_early(struct device *dev, pm_message_t state, bool asyn if (!dev->power.is_late_suspended) goto Out; - dpm_wait_for_superior(dev, async); + if (!dpm_wait_for_superior(dev, async)) + goto Out; callback = dpm_subsys_resume_early_cb(dev, state, &info); @@ -944,7 +974,9 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) goto Complete; } - dpm_wait_for_superior(dev, async); + if (!dpm_wait_for_superior(dev, async)) + goto Complete; + dpm_watchdog_set(&wd, dev); device_lock(dev); |