* Re: [tip:x86/tsc] x86: Check tsc available/disabled in the delayed init function
[not found] <tip-a8760eca6cf60ed303ad494ef45901f63165d2c8@git.kernel.org>
@ 2010-12-13 19:22 ` john stultz
0 siblings, 0 replies; only message in thread
From: john stultz @ 2010-12-13 19:22 UTC (permalink / raw)
To: linux-kernel, mingo, hpa, tglx; +Cc: linux-tip-commits
On Mon, 2010-12-13 at 10:37 +0000, tip-bot for Thomas Gleixner wrote:
> Commit-ID: a8760eca6cf60ed303ad494ef45901f63165d2c8
> Gitweb: http://git.kernel.org/tip/a8760eca6cf60ed303ad494ef45901f63165d2c8
> Author: Thomas Gleixner <tglx@linutronix.de>
> AuthorDate: Mon, 13 Dec 2010 11:28:02 +0100
> Committer: Thomas Gleixner <tglx@linutronix.de>
> CommitDate: Mon, 13 Dec 2010 11:35:05 +0100
>
> 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 <tglx@linutronix.de>
> Cc: John Stultz <johnstul@us.ibm.com>
Thanks for catching this!
Acked-by: John Stultz <johnstul@us.ibm.com>
> ---
> arch/x86/kernel/tsc.c | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
> index dc1393e..356a0d4 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: */
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