diff options
| author | Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | 2005-09-15 18:20:00 +0200 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2005-11-30 09:23:52 +0100 |
| commit | 4c0335526c95d90a1d958e0059f40a5745fc7c5d (patch) | |
| tree | 9a4f6f84f9ba1b1a838e71799470b2acab9e2ba7 /drivers/acpi/processor_idle.c | |
| parent | [ACPI] Prefer _CST over FADT for C-state capabilities (diff) | |
| download | linux-4c0335526c95d90a1d958e0059f40a5745fc7c5d.tar.xz linux-4c0335526c95d90a1d958e0059f40a5745fc7c5d.zip | |
[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<venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
(cherry picked from 28b86b368af3944eb383078fc5797caf2dc8ce44 commit)
Diffstat (limited to 'drivers/acpi/processor_idle.c')
| -rw-r--r-- | drivers/acpi/processor_idle.c | 19 |
1 files changed, 19 insertions, 0 deletions
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; |