[ACPI] Add support for FADT P_LVL2_UP flag

[karo-tx-linux.git] / drivers / acpi / processor_idle.c

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 70d8a6ec0920f1589525395a1550360a26cbd54f..83fd1b6c10c41e7ddb62c271661523ef3affafc9 100644 (file)
--- 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;
@@ -690,7 +709,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 
        /* Validate number of power states discovered */
        if (pr->power.count < 2)
-               status = -ENODEV;
+               status = -EFAULT;
 
       end:
        acpi_os_free(buffer.pointer);
@@ -841,11 +860,11 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
         * this function */
 
        result = acpi_processor_get_power_info_cst(pr);
-       if ((result) || (acpi_processor_power_verify(pr) < 2)) {
+       if (result == -ENODEV)
                result = acpi_processor_get_power_info_fadt(pr);
-               if ((result) || (acpi_processor_power_verify(pr) < 2))
-                       result = acpi_processor_get_power_info_default_c1(pr);
-       }
+
+       if ((result) || (acpi_processor_power_verify(pr) < 2))
+               result = acpi_processor_get_power_info_default_c1(pr);
 
        /*
         * Set Default Policy