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| author | Len Brown <len.brown@intel.com> | 2009-04-21 00:50:11 -0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-04-22 19:22:18 -0400 |
| commit | a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2 (patch) | |
| tree | 43bd9f429a954f30c3df8d3fd53c73588d135d04 /drivers/acpi | |
| parent | 091069740304c979f957ceacec39c461d0192158 (diff) | |
| download | linux-a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2.tar.gz linux-a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2.tar.bz2 linux-a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2.zip | |
ACPI: idle: mark_tsc_unstable() at init-time, not run-time
The c2 and c3 idle handlers check tsc_halts_in_c()
after every time they return from idle. Um, when?:-)
Move this check to init-time to remove the unnecessary
run-time overhead, and also to have the check complete before
the first entry into the idle handler.
ff69f2bba67bd45514923aaedbf40fe351787c59
(acpi: fix of pmtimer overflow that make Cx states time incorrect)
replaced the hard-coded use of the PM-timer inside idle,
with ktime_get_readl(), which possibly uses the TSC --
so it is now especially prudent to detect a broken TSC
before entering idle.
http://bugzilla.kernel.org/show_bug.cgi?id=13087
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/processor_idle.c | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 6fe121434ffb..9d1f01ee65db 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -581,6 +581,11 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { struct acpi_processor_cx *cx = &pr->power.states[i]; +#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) + /* TSC could halt in idle, so notify users */ + if (tsc_halts_in_c(cx->type)) + mark_tsc_unstable("TSC halts in idle");; +#endif switch (cx->type) { case ACPI_STATE_C1: cx->valid = 1; @@ -871,11 +876,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, kt2 = ktime_get_real(); idle_time = ktime_to_us(ktime_sub(kt2, kt1)); -#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) - /* TSC could halt in idle, so notify users */ - if (tsc_halts_in_c(cx->type)) - mark_tsc_unstable("TSC halts in idle");; -#endif sleep_ticks = us_to_pm_timer_ticks(idle_time); /* Tell the scheduler how much we idled: */ @@ -989,11 +989,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, spin_unlock(&c3_lock); } -#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) - /* TSC could halt in idle, so notify users */ - if (tsc_halts_in_c(ACPI_STATE_C3)) - mark_tsc_unstable("TSC halts in idle"); -#endif sleep_ticks = us_to_pm_timer_ticks(idle_time); /* Tell the scheduler how much we idled: */ sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); |