Pull 5165 into release branch

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);
-	}
 
 	/*
 	 * Set Default Policy