Commit a0bf284b authored by Len Brown's avatar Len Brown

ACPI: Idle C-states disabled by max_cstate should not disable the TSC

Processor idle power states C2 and C3 stop the TSC on many machines.
Linux recognizes this situation and marks the TSC as unstable:

Marking TSC unstable due to TSC halts in idle

But if those same machines are booted with "processor.max_cstate=1",
then there is no need to validate C2 and C3, and no need to
disable the TSC, which can be reliably used as a clocksource.
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 520daf72
...@@ -582,7 +582,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) ...@@ -582,7 +582,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
pr->power.timer_broadcast_on_state = INT_MAX; pr->power.timer_broadcast_on_state = INT_MAX;
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
struct acpi_processor_cx *cx = &pr->power.states[i]; struct acpi_processor_cx *cx = &pr->power.states[i];
switch (cx->type) { switch (cx->type) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment