The 'intel_idle_probe' probes the CPU and sets the CPU notifier.
But if later on during the module initialization we fail (say
in cpuidle_register_driver), we stop loading, but we neglect
to unregister the CPU notifier. This means that during CPU
hotplug events the system will fail:
calling intel_idle_init+0x0/0x326 @ 1
intel_idle: MWAIT substates: 0x1120
intel_idle: v0.4 model 0x2A
intel_idle: lapic_timer_reliable_states 0xffffffff
intel_idle: intel_idle yielding to none
initcall intel_idle_init+0x0/0x326 returned -19 after 14 usecs
... some time later, offlining and onlining a CPU:
This patch fixes that by moving the CPU notifier registration
as the last item to be done by the module.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: notifier is registered only if we do not have ARAT] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>