Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull Intel SoC changes from Ingo Molnar:
 "Improved Intel SoC platform support"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, tsc, apic: Unbreak static (MSR) calibration when CONFIG_X86_LOCAL_APIC=n
  x86, tsc: Add static (MSR) TSC calibration on Intel Atom SoCs
  arch: x86: New MailBox support driver for Intel SOC's

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 6377fb28b958..a3acbac2ee72 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -651,6 +651,16 @@ unsigned long native_calibrate_tsc(void)
 	unsigned long flags, latch, ms, fast_calibrate;
 	int hpet = is_hpet_enabled(), i, loopmin;
 
+	/* Calibrate TSC using MSR for Intel Atom SoCs */
+	local_irq_save(flags);
+	i = try_msr_calibrate_tsc(&fast_calibrate);
+	local_irq_restore(flags);
+	if (i >= 0) {
+		if (i == 0)
+			pr_warn("Fast TSC calibration using MSR failed\n");
+		return fast_calibrate;
+	}
+
 	local_irq_save(flags);
 	fast_calibrate = quick_pit_calibrate();
 	local_irq_restore(flags);