x86: use the correct cpuid method to detect MWAIT support for C states

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / process_32.c

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 35a6f318c5417eabc937092970c32f7e470a1bf4..9f45a51af968be31679923ea94bf83a9e0c60e88 100644 (file)
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -198,6 +198,9 @@ void cpu_idle(void)
                        rmb();
                        idle = pm_idle;
 
+                       if (rcu_pending(cpu))
+                               rcu_check_callbacks(cpu, 0);
+
                        if (!idle)
                                idle = default_idle;
 
@@ -282,9 +285,17 @@ static void mwait_idle(void)
        mwait_idle_with_hints(0, 0);
 }
 
+static int mwait_usable(const struct cpuinfo_x86 *c)
+{
+       if (force_mwait)
+               return 1;
+       /* Any C1 states supported? */
+       return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0;
+}
+
 void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
 {
-       if (cpu_has(c, X86_FEATURE_MWAIT)) {
+       if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
                printk("monitor/mwait feature present.\n");
                /*
                 * Skip, if setup has overridden idle.
@@ -379,7 +390,7 @@ void __show_registers(struct pt_regs *regs, int all)
 void show_regs(struct pt_regs *regs)
 {
        __show_registers(regs, 1);
-       show_trace(NULL, regs, &regs->sp);
+       show_trace(NULL, regs, &regs->sp, regs->bp);
 }
 
 /*