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    Subject[PATCH v2 1/7] x86,tsc: Always unregister clocksource_tsc_early
    Don't leave the tsc-early clocksource registered if it errors out
    early.

    This was reported by Diego, who on his Core2 era machine got TSC
    invalidated while it was running with tsc-early (due to C-states).
    This results in keeping tsc-early with very bad effects.

    Reported-and-Tested-by: Diego Viola <diego.viola@gmail.com>
    Fixes: aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource")
    Cc: stable@kernel.org
    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    ---
    arch/x86/kernel/tsc.c | 10 ++++++----
    1 file changed, 6 insertions(+), 4 deletions(-)

    --- a/arch/x86/kernel/tsc.c
    +++ b/arch/x86/kernel/tsc.c
    @@ -1244,7 +1244,7 @@ static void tsc_refine_calibration_work(

    /* Don't bother refining TSC on unstable systems */
    if (tsc_unstable)
    - return;
    + goto unreg;

    /*
    * Since the work is started early in boot, we may be
    @@ -1297,11 +1297,12 @@ static void tsc_refine_calibration_work(

    out:
    if (tsc_unstable)
    - return;
    + goto unreg;

    if (boot_cpu_has(X86_FEATURE_ART))
    art_related_clocksource = &clocksource_tsc;
    clocksource_register_khz(&clocksource_tsc, tsc_khz);
    +unreg:
    clocksource_unregister(&clocksource_tsc_early);
    }

    @@ -1311,8 +1312,8 @@ static int __init init_tsc_clocksource(v
    if (!boot_cpu_has(X86_FEATURE_TSC) || tsc_disabled > 0 || !tsc_khz)
    return 0;

    - if (check_tsc_unstable())
    - return 0;
    + if (tsc_unstable)
    + goto unreg;

    if (tsc_clocksource_reliable)
    clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
    @@ -1328,6 +1329,7 @@ static int __init init_tsc_clocksource(v
    if (boot_cpu_has(X86_FEATURE_ART))
    art_related_clocksource = &clocksource_tsc;
    clocksource_register_khz(&clocksource_tsc, tsc_khz);
    +unreg:
    clocksource_unregister(&clocksource_tsc_early);
    return 0;
    }

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