diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2016-12-13 13:14:17 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-12-15 11:44:29 +0100 |
| commit | 6a369583178d0b89c2c3919c4456ee22fee0f249 (patch) | |
| tree | eaaebee6ac4102b724483d19a1c6f920c5406b67 /arch/x86/kernel/tsc.c | |
| parent | 31f8a651fc5784a9e6f482be5ef0dd111a535e88 (diff) | |
x86/tsc: Validate TSC_ADJUST after resume
Some 'feature' BIOSes fiddle with the TSC_ADJUST register during
suspend/resume which renders the TSC unusable.
Add sanity checks into the resume path and restore the
original value if it was adjusted.
Reported-and-tested-by: Roland Scheidegger <rscheidegger_lists@hispeed.ch>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bruce Schlobohm <bruce.schlobohm@intel.com>
Cc: Kevin Stanton <kevin.b.stanton@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Allen Hung <allen_hung@dell.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20161213131211.317654500@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/tsc.c')
| -rw-r--r-- | arch/x86/kernel/tsc.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 2bb8de4f3b39..bfb541a5bb48 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1080,6 +1080,11 @@ static void detect_art(void) static struct clocksource clocksource_tsc; +static void tsc_resume(struct clocksource *cs) +{ + tsc_verify_tsc_adjust(true); +} + /* * We used to compare the TSC to the cycle_last value in the clocksource * structure to avoid a nasty time-warp. This can be observed in a @@ -1112,6 +1117,7 @@ static struct clocksource clocksource_tsc = { .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, .archdata = { .vclock_mode = VCLOCK_TSC }, + .resume = tsc_resume, }; void mark_tsc_unstable(char *reason) |