, but the user might select PIT
    via the sysfs override, which would break the box as the time
    readout is unusable.

Unregister the PIT clocksource when the PIT clock event device is switched
into shutdown / oneshot mode.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
ŚM