x86: fix setup of cyc2ns in tsc_64.c
When the TSC is calibrated against the PIT due to the nonavailability
of PMTIMER/HPET or due to SMI interference then the setup of the per
CPU cyc2ns variables is skipped. This is unlikely to happen but it
would definitely render sched_clock() unusable.
This was introduced with commit 53d517cdbaac704352b3d0c10fecb99e0b54572e
x86: scale cyc_2_nsec according to CPU frequency
Update the per CPU cyc2ns variables in all exit pathes of tsc_calibrate.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index fcc16e5..1784b80 100644
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -227,14 +227,14 @@
/* hpet or pmtimer available ? */
if (!hpet && !pm1 && !pm2) {
printk(KERN_INFO "TSC calibrated against PIT\n");
- return;
+ goto out;
}
/* Check, whether the sampling was disturbed by an SMI */
if (tsc1 == ULONG_MAX || tsc2 == ULONG_MAX) {
printk(KERN_WARNING "TSC calibration disturbed by SMI, "
"using PIT calibration result\n");
- return;
+ goto out;
}
tsc2 = (tsc2 - tsc1) * 1000000L;
@@ -255,6 +255,7 @@
tsc_khz = tsc2 / tsc1;
+out:
for_each_possible_cpu(cpu)
set_cyc2ns_scale(tsc_khz, cpu);
}