x86: apic - fix unused vars warning in calibrate_APIC_clock
If we don't have CONFIG_X86_PM_TIMER=y compiler warns about
unused variables. Move PM timer based calibration into a
separate function and make the code cleaner and the compiler
happy as well.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index d730e8d..7841169 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -538,14 +538,51 @@
}
}
+static int __init calibrate_by_pmtimer(long deltapm, long *delta)
+{
+ const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
+ const long pm_thresh = pm_100ms / 100;
+ unsigned long mult;
+ u64 res;
+
+#ifndef CONFIG_X86_PM_TIMER
+ return -1;
+#endif
+
+ apic_printk(APIC_VERBOSE, "... PM timer delta = %ld\n", deltapm);
+
+ /* Check, if the PM timer is available */
+ if (!deltapm)
+ return -1;
+
+ mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
+
+ if (deltapm > (pm_100ms - pm_thresh) &&
+ deltapm < (pm_100ms + pm_thresh)) {
+ apic_printk(APIC_VERBOSE, "... PM timer result ok\n");
+ } else {
+ res = (((u64)deltapm) * mult) >> 22;
+ do_div(res, 1000000);
+ printk(KERN_WARNING "APIC calibration not consistent "
+ "with PM Timer: %ldms instead of 100ms\n",
+ (long)res);
+ /* Correct the lapic counter value */
+ res = (((u64)(*delta)) * pm_100ms);
+ do_div(res, deltapm);
+ printk(KERN_INFO "APIC delta adjusted to PM-Timer: "
+ "%lu (%ld)\n", (unsigned long)res, *delta);
+ *delta = (long)res;
+ }
+
+ return 0;
+}
+
static int __init calibrate_APIC_clock(void)
{
struct clock_event_device *levt = &__get_cpu_var(lapic_events);
- const long pm_100ms = PMTMR_TICKS_PER_SEC/10;
- const long pm_thresh = pm_100ms/100;
void (*real_handler)(struct clock_event_device *dev);
unsigned long deltaj;
- long delta, deltapm;
+ long delta;
int pm_referenced = 0;
local_irq_disable();
@@ -575,36 +612,9 @@
delta = lapic_cal_t1 - lapic_cal_t2;
apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
-#ifdef CONFIG_X86_PM_TIMER
- /* Check, if the PM timer is available */
- deltapm = lapic_cal_pm2 - lapic_cal_pm1;
- apic_printk(APIC_VERBOSE, "... PM timer delta = %ld\n", deltapm);
-
- if (deltapm) {
- unsigned long mult;
- u64 res;
-
- mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
-
- if (deltapm > (pm_100ms - pm_thresh) &&
- deltapm < (pm_100ms + pm_thresh)) {
- apic_printk(APIC_VERBOSE, "... PM timer result ok\n");
- } else {
- res = (((u64) deltapm) * mult) >> 22;
- do_div(res, 1000000);
- printk(KERN_WARNING "APIC calibration not consistent "
- "with PM Timer: %ldms instead of 100ms\n",
- (long)res);
- /* Correct the lapic counter value */
- res = (((u64) delta) * pm_100ms);
- do_div(res, deltapm);
- printk(KERN_INFO "APIC delta adjusted to PM-Timer: "
- "%lu (%ld)\n", (unsigned long) res, delta);
- delta = (long) res;
- }
- pm_referenced = 1;
- }
-#endif
+ /* we trust the PM based calibration if possible */
+ pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
+ &delta);
/* Calculate the scaled math multiplication factor */
lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
@@ -646,7 +656,10 @@
levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
- /* We trust the pm timer based calibration */
+ /*
+ * PM timer calibration failed or not turned on
+ * so lets try APIC timer based calibration
+ */
if (!pm_referenced) {
apic_printk(APIC_VERBOSE, "... verify APIC timer\n");