ACPI: idle: fix init-time TSC check regression

A previous 2.6.30 patch, a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2,
(ACPI: idle: mark_tsc_unstable() at init-time, not run-time)
erroneously disabled the TSC on systems that did not actually
have valid deep C-states.

Move the check after the deep-C-states are validated,
via new helper, tsc_check_state(), hich replaces tsc_halts_in_c().

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Frans Pop <elendil@planet.nl>

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index f7ca8c5..e39a40a 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -216,7 +216,7 @@ int acpi_processor_resume(struct acpi_device * device)
 }
 
 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
-static int tsc_halts_in_c(int state)
+static void tsc_check_state(int state)
 {
        switch (boot_cpu_data.x86_vendor) {
        case X86_VENDOR_AMD:
@@ -226,13 +226,17 @@ static int tsc_halts_in_c(int state)
                 * C/P/S0/S1 states when this bit is set.
                 */
                if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
-                       return 0;
+                       return;
 
                /*FALL THROUGH*/
        default:
-               return state > ACPI_STATE_C1;
+               /* TSC could halt in idle, so notify users */
+               if (state > ACPI_STATE_C1)
+                       mark_tsc_unstable("TSC halts in idle");
        }
 }
+#else
+static void tsc_check_state(int state) { return; }
 #endif
 
 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
@@ -581,11 +585,6 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
                struct acpi_processor_cx *cx = &pr->power.states[i];
 
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
-               /* TSC could halt in idle, so notify users */
-               if (tsc_halts_in_c(cx->type))
-                       mark_tsc_unstable("TSC halts in idle");;
-#endif
                switch (cx->type) {
                case ACPI_STATE_C1:
                        cx->valid = 1;
@@ -603,6 +602,8 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
                                acpi_timer_check_state(i, pr, cx);
                        break;
                }
+               if (cx->valid)
+                       tsc_check_state(cx->type);
 
                if (cx->valid)
                        working++;