x86: tsc: Prevent delayed init if initial tsc calibration failed

commit a8760ec (x86: Check tsc available/disabled in the delayed init
function) missed to prevent the setup of the delayed init function in
case the initial tsc calibration failed. This results in the same
divide by zero bug as we have seen without the tsc disabled check.

Skip the delayed work setup when tsc_khz (the initial calibration
value) is 0.

Bisected-and-tested-by: Kirill A. Shutemov <kas@openvz.org>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 356a0d4..463901e 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -965,7 +965,7 @@ out:
 
 static int __init init_tsc_clocksource(void)
 {
-       if (!cpu_has_tsc || tsc_disabled > 0)
+       if (!cpu_has_tsc || tsc_disabled > 0 || !tsc_khz)
                return 0;
 
        if (tsc_clocksource_reliable)