- /*
- * 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);
- }
- }