On Thu, Jan 30, 2014 at 06:28:52PM +0100, Daniel Lezcano wrote:

Ok, I think the mess is coming from 'default_idle' which does not re-enable
the local_irq but used from different places like amd_e400_idle and
apm_cpu_idle.

void default_idle(void)
{
        trace_cpu_idle_rcuidle(1, smp_processor_id());
        safe_halt();
        trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}

Considering the system configured without cpuidle because this one *always*
enable the local irq, we have the different cases:

x86_idle = default_idle();
==> local_irq_enable is missing

safe_halt() is "sti; hlt" and so very much does the irq_enable.