diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 5b6a9865300e..83fd1b6c10c4 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -280,6 +280,16 @@ static void acpi_processor_idle(void) cx->usage++; +#ifdef CONFIG_HOTPLUG_CPU + /* + * Check for P_LVL2_UP flag before entering C2 and above on + * an SMP system. We do it here instead of doing it at _CST/P_LVL + * detection phase, to work cleanly with logical CPU hotplug. + */ + if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && + !pr->flags.has_cst && acpi_fadt.plvl2_up) + cx->type = ACPI_STATE_C1; +#endif /* * Sleep: * ------ @@ -534,6 +544,15 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) pr->power.states[ACPI_STATE_C0].valid = 1; pr->power.states[ACPI_STATE_C1].valid = 1; +#ifndef CONFIG_HOTPLUG_CPU + /* + * Check for P_LVL2_UP flag before entering C2 and above on + * an SMP system. + */ + if ((num_online_cpus() > 1) && acpi_fadt.plvl2_up) + return_VALUE(-ENODEV); +#endif + /* determine C2 and C3 address from pblk */ pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;