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authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>2005-09-15 20:20:00 +0400
committerLen Brown <len.brown@intel.com>2005-11-30 11:23:52 +0300
commit4c0335526c95d90a1d958e0059f40a5745fc7c5d (patch)
tree9a4f6f84f9ba1b1a838e71799470b2acab9e2ba7 /drivers/acpi
parent6d93c64803a5fea84839789aae13290419c62d92 (diff)
downloadlinux-4c0335526c95d90a1d958e0059f40a5745fc7c5d.tar.xz
[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')
-rw-r--r--drivers/acpi/processor_idle.c19
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;