Commit 3d5b6fb47a ("ACPI: Kill overly
verbose "power state" log messages") removed the actual use of this
variable, but didn't remove the variable itself, resulting in build
warnings like
drivers/acpi/processor_idle.c: In function ‘acpi_processor_power_init’:
drivers/acpi/processor_idle.c:1169: warning: unused variable ‘i’
Just get rid of the now unused variable.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I was recently lucky enough to get a 64-CPU system, so my kernel log
ends up with 64 lines like:
ACPI: CPU0 (power states: C1[C1] C2[C3])
This is pretty useless clutter because this info is already available
after boot from both /sys/devices/system/cpu/cpu*/cpuidle/state?/ as
well as /proc/acpi/processor/CPU*/power.
So just delete the code that prints the C-states in processor_idle.c.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Linux/ACPI core files using internal.h all PREFIX "ACPI: ",
however, not all ACPI drivers use/want it -- and they
should not have to #undef PREFIX to define their own.
Add GPL commment to internal.h while we are there.
This does not change any actual console output,
asside from a whitespace fix.
Signed-off-by: Len Brown <len.brown@intel.com>
Currently clockevents_notify() is called with interrupts enabled at
some places and interrupts disabled at some other places.
This results in a deadlock in this scenario.
cpu A holds clockevents_lock in clockevents_notify() with irqs enabled
cpu B waits for clockevents_lock in clockevents_notify() with irqs disabled
cpu C doing set_mtrr() which will try to rendezvous of all the cpus.
This will result in C and A come to the rendezvous point and waiting
for B. B is stuck forever waiting for the spinlock and thus not
reaching the rendezvous point.
Fix the clockevents code so that clockevents_lock is taken with
interrupts disabled and thus avoid the above deadlock.
Also call lapic_timer_propagate_broadcast() on the destination cpu so
that we avoid calling smp_call_function() in the clockevents notifier
chain.
This issue left us wondering if we need to change the MTRR rendezvous
logic to use stop machine logic (instead of smp_call_function) or add
a check in spinlock debug code to see if there are other spinlocks
which gets taken under both interrupts enabled/disabled conditions.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: "Brown Len" <len.brown@intel.com>
LKML-Reference: <1250544899.2709.210.camel@sbs-t61.sc.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Now whether the ACPI processor proc I/F is registered depends on the
CONFIG_PROC. It had better depend on the CONFIG_ACPI_PROCFS.
When the CONFIG_ACPI_PROCFS is unset in kernel configuration, the
ACPI processor proc I/F won't be registered.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
cosmetic only. The lapic_timer workaround routines
are specific to the lapic_timer, and are not acpi-generic.
old:
acpi_timer_check_state()
acpi_propagate_timer_broadcast()
acpi_state_timer_broadcast()
new:
lapic_timer_check_state()
lapic_timer_propagate_broadcast()
lapic_timer_state_broadcast()
also, simplify the code in acpi_processor_power_verify()
so that lapic_timer_check_state() is simply called
from one place for all valid C-states, including C1.
Signed-off-by: Len Brown <len.brown@intel.com>
ARB_DISABLE is a NOP on all of the recent Intel platforms.
For such platforms, reduce contention on c3_lock
by skipping the fake ARB_DISABLE.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
When AMD C1E is enabled, local APIC timer will stop even in C1. To avoid
suspend/resume hang, this patch removes C1 and replace it with a cpu_relax() in
suspend/resume path. This hasn't any impact in runtime path.
http://bugzilla.kernel.org/show_bug.cgi?id=13233
[ impact: avoid suspend/resume hang in AMD CPU with C1E enabled ]
Tested-by: Dmitry Lyzhyn <thisistempbox@yahoo.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
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: Len Brown <len.brown@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
A previous 2.6.30 patch, a71e4917dc,
(ACPI: idle: mark_tsc_unstable() at init-time, not run-time)
erroneously disabled the TSC on systems that did not actually
have valid deep C-states.
Move the check after the deep-C-states are validated,
via new helper, tsc_check_state(), hich replaces tsc_halts_in_c().
Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Frans Pop <elendil@planet.nl>
In 2.6.29,
31878dd86b
"ACPI: remove BM_RLD access from idle entry path"
moved BM_RLD initialization to init-time from run time.
But we discovered that some BIOS do not restore BM_RLD
after suspend, causing device errors on C3 and C4
after resume. So now the kernel restores BM_RLD.
http://bugzilla.kernel.org/show_bug.cgi?id=13032
Signed-off-by: Len Brown <len.brown@intel.com>
Linux tells ICH4 users that they can (manually) invoke
"hpet=force" to enable the undocumented ICH-4M HPET.
The HPET becomes available for both clocksource and clockevents.
But as of ff69f2bba6
(acpi: fix of pmtimer overflow that make Cx states time incorrect)
the HPET may be used via clocksource for idle accounting, and
hpet=force on an ICH4 box hangs boot.
It turns out that touching the MMIO HPET withing
the ARB_DIS part of C3 will hang the hardware.
The fix is to simply move the timer access outside
the ARB_DIS region. This is a no-op on modern hardware
because ARB_DIS is no longer used.
http://bugzilla.kernel.org/show_bug.cgi?id=13087
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Linux-2.6.29 deleted the legacy ACPI idle handler, leaving
the CPU_IDLE handler, which does not track bus master activity.
So delete the unused bm_activity field -- it is confusing to
print an always zero value.
This patch could break programs that parse
/proc/acpi/processor/*/power, since it deletes this
line from that file:
bus master activity: 00000000
http://bugzilla.kernel.org/show_bug.cgi?id=13145
is not fixed by this patch, but provoked this patch.
Signed-off-by: Len Brown <len.brown@intel.com>
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.
ff69f2bba6
(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>
Add support for Always Running APIC timer, CPUID_0x6_EAX_Bit2.
This bit means the APIC timer continues to run even when CPU is
in deep C-states.
The advantage is that we can use LAPIC timer on these CPUs
always, and there is no need for "slow to read and program"
external timers (HPET/PIT) and the timer broadcast logic
and related code in C-state entry and exit.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Len Brown <len.brown@intel.com>
