PM / hibernate: Fix restore hang in freeze_processes()
PM / hibernate: Fix restore hang in freeze_processes()

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 <0f52817bee885ee34abeca6e40ef7cb52659e8aa@linaro.org>
Acked-by: Ming Lei <8d0fc11caeb4659419f0ba3104eb4a9d30848d42@canonical.com>
Cc: All applicable <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <27ffc44a8ec6a212fba98cfc3246c6ce8ab131e0@intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs