During restore, pm_notifier chain are called with PM_RESTORE_PREPARE. The firmware_class driver handler fw_pm_notify does not have a handler for this. As a result, it keeps a reader on the kmod.c umhelper_sem. During freeze_processes, the call to __usermodehelper_disable tries to take a write lock on this semaphore and hangs waiting.
Signed-off-by: Sebastian Capella sebastian.capella@linaro.org Cc: Russ Dill Russ.Dill@ti.com Cc: Ming Lei ming.lei@canonical.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/base/firmware_class.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index eb8fb94..e2b51f8 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -1541,6 +1541,7 @@ static int fw_pm_notify(struct notifier_block *notify_block, switch (mode) { case PM_HIBERNATION_PREPARE: case PM_SUSPEND_PREPARE: + case PM_RESTORE_PREPARE: kill_requests_without_uevent(); device_cache_fw_images(); break;