Don't leave the tsc-early clocksource registered if we error out early.

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

Reported-and-Tested-by: Diego Viola <[email protected]>
Fixes: aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource")
Cc: [email protected]
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
---
 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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