From 4c0335526c95d90a1d958e0059f40a5745fc7c5d Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Thu, 15 Sep 2005 12:20:00 -0400 Subject: [ACPI] Add support for FADT P_LVL2_UP flag which tells us if C2 is valid for UP-only, or SMP. As there is no separate bit for C3, use P_LVL2_UP bit to cover both C2 and C3. http://bugzilla.kernel.org/show_bug.cgi?id=5165 Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown (cherry picked from 28b86b368af3944eb383078fc5797caf2dc8ce44 commit) --- drivers/acpi/processor_idle.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'drivers/acpi') 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; -- cgit v1.2.3-58-ga151