From a8760eca6cf60ed303ad494ef45901f63165d2c8 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 13 Dec 2010 11:28:02 +0100 Subject: [PATCH] x86: Check tsc available/disabled in the delayed init function The delayed TSC init function does not check whether the system has no TSC or TSC is disabled at the kernel command line, which results in a crash in the work queue based extended calibration due to division by zero because the basic calibration never happened. Add the missing checks and do not touch TSC when not available or disabled. Signed-off-by: Thomas Gleixner Cc: John Stultz --- arch/x86/kernel/tsc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index dc1393e7cbfb..356a0d455cf9 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -965,6 +965,9 @@ out: static int __init init_tsc_clocksource(void) { + if (!cpu_has_tsc || tsc_disabled > 0) + return 0; + if (tsc_clocksource_reliable) clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY; /* lower the rating if we already know its unstable: */ -- 2.20.1