[PATCH] fix i386/x86_64 idle routine selection

This was broken when the mwait stuff went in since it executes after the
initial idle_setup() has already selected an idle routine and overrides it
with default_idle.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Zwane Mwaikambo <zwane@linuxpower.ca>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/process.c

@@ -183,18 +183,13 @@ void __init select_idle_routine(const struct cpuinfo_x86 *c)
 		printk("monitor/mwait feature present.\n");
 		/*
 		 * Skip, if setup has overridden idle.
-		 * Also, take care of system with asymmetric CPUs.
-		 * Use, mwait_idle only if all cpus support it.
-		 * If not, we fallback to default_idle()
+		 * One CPU supports mwait => All CPUs supports mwait
 		 */
 		if (!pm_idle) {
 			printk("using mwait in idle threads.\n");
 			pm_idle = mwait_idle;
 		}
-		return;
 	}
-	pm_idle = default_idle;
-	return;
 }
 
 static int __init idle_setup (char *str)

arch/x86_64/kernel/process.c

@@ -168,9 +168,7 @@ void __init select_idle_routine(const struct cpuinfo_x86 *c)
 	if (cpu_has(c, X86_FEATURE_MWAIT)) {
 		/*
 		 * Skip, if setup has overridden idle.
-		 * Also, take care of system with asymmetric CPUs.
-		 * Use, mwait_idle only if all cpus support it.
-		 * If not, we fallback to default_idle()
+		 * One CPU supports mwait => All CPUs supports mwait
 		 */
 		if (!pm_idle) {
 			if (!printed) {
@@ -179,10 +177,7 @@ void __init select_idle_routine(const struct cpuinfo_x86 *c)
 			}
 			pm_idle = mwait_idle;
 		}
-		return;
 	}
-	pm_idle = default_idle;
-	return;
 }
 
 static int __init idle_setup (char *str)