Hi folks, I have briefly verified the patch for Wheezy's 3.13 and 3.14 bpo kernels. The reference to acpi_os_wait_events_complete is gone.
Hope this helps Harri
--- kernel/nv-acpi.c.orig 2013-12-30 09:23:36.000000000 +0100 +++ kernel/nv-acpi.c 2014-06-05 11:34:27.194829353 +0200 @@ -303,7 +303,10 @@ if (pNvAcpiObject->notify_handler_installed) { +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 13, 0) +/* beginning with 3.13, acpi_remove_notify_handler() waits for events to finish */ NV_ACPI_OS_WAIT_EVENTS_COMPLETE(); +#endif // remove event notifier status = acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, nv_acpi_event);