linux-toradex.git/drivers/acpi/processor_idle.c, branch v3.10.78

cpuidle: ACPI: do not overwrite name and description of C0

2015-04-19T08:10:49+00:00

commit c7e8bdf5872c5a8f5a6494e16fe839c38a0d3d3d upstream.

Fix a bug that leads to showing the name and description of C-state C0
as "" in sysfs after the ACPI C-states changed (e.g. after AC->DC
or DC->AC
transition).

The function poll_idle_init() in drivers/cpuidle/driver.c initializes the
state 0 during cpuidle_register_driver(), so we better do not overwrite it
again with '\0' during acpi_processor_cst_has_changed().

Signed-off-by: Thomas Schlichter 
Reviewed-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI / cpuidle: fix deadlock between cpuidle_lock and cpu_hotplug.lock

2014-09-17T16:03:59+00:00

commit 6726655dfdd2dc60c035c690d9f10cb69d7ea075 upstream.

There is a following AB-BA dependency between cpu_hotplug.lock and
cpuidle_lock:

1) cpu_hotplug.lock -> cpuidle_lock
enable_nonboot_cpus()
 _cpu_up()
  cpu_hotplug_begin()
   LOCK(cpu_hotplug.lock)
 cpu_notify()
  ...
  acpi_processor_hotplug()
   cpuidle_pause_and_lock()
    LOCK(cpuidle_lock)

2) cpuidle_lock -> cpu_hotplug.lock
acpi_os_execute_deferred() workqueue
 ...
 acpi_processor_cst_has_changed()
  cpuidle_pause_and_lock()
   LOCK(cpuidle_lock)
  get_online_cpus()
   LOCK(cpu_hotplug.lock)

Fix this by reversing the order acpi_processor_cst_has_changed() does
thigs -- let it first execute the protection against CPU hotplug by
calling get_online_cpus() and obtain the cpuidle lock only after that (and
perform the symmentric change when allowing CPUs hotplug again and
dropping cpuidle lock).

Spotted by lockdep.

Signed-off-by: Jiri Kosina 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

sched, idle: Fix the idle polling state logic

2013-11-29T19:11:42+00:00

commit ea8117478918a4734586d35ff530721b682425be upstream.

Mike reported that commit 7d1a9417 ("x86: Use generic idle loop")
regressed several workloads and caused excessive reschedule
interrupts.

The patch in question failed to notice that the x86 code had an
inverted sense of the polling state versus the new generic code (x86:
default polling, generic: default !polling).

Fix the two prominent x86 mwait based idle drivers and introduce a few
new generic polling helpers (fixing the wrong smp_mb__after_clear_bit
usage).

Also switch the idle routines to using tif_need_resched() which is an
immediate TIF_NEED_RESCHED test as opposed to need_resched which will
end up being slightly different.

Reported-by: Mike Galbraith 
Signed-off-by: Peter Zijlstra 
Cc: lenb@kernel.org
Cc: tglx@linutronix.de
Link: http://lkml.kernel.org/n/tip-nc03imb0etuefmzybzj7sprf@git.kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

ACPI / PM: Move processor suspend/resume to syscore_ops

2013-05-12T12:03:14+00:00

The system suspend routine of the ACPI processor driver saves
the BUS_MASTER_RLD register and its resume routine restores it.
However, there can be only one such register in the system and it
really should be saved after non-boot CPUs have been offlined and
restored before they are put back online during resume.

For this reason, move the saving and restoration of BUS_MASTER_RLD
to syscore suspend and syscore resume, respectively, and drop the no
longer necessary suspend/resume callbacks from the ACPI processor
driver.

Signed-off-by: Rafael J. Wysocki

cpuidle: remove en_core_tk_irqen flag

2013-04-23T11:45:22+00:00

The en_core_tk_irqen flag is set in all the cpuidle driver which
means it is not necessary to specify this flag.

Remove the flag and the code related to it.

Signed-off-by: Daniel Lezcano 
Acked-by: Kevin Hilman   # for mach-omap2/*
Signed-off-by: Rafael J. Wysocki

cpuidle / ACPI: recover percpu ACPI processor cstate

2013-04-02T13:31:28+00:00

Commit ac3ebafa81af76d6 "ACPI / idle: remove usage of the statedata"
changed the percpu processor cstate to a unified cstate in ACPI idle.
That caused all our NHM boxes to boot hang or panic.

2178751 Task dump for CPU 1:
	2178752 swapper/1       R  running task     6736     0      1 0x00000000
	2178753  ffff8801e8029dc8 ffffffff8101cf96 ffff8801e8029e28 ffffffff813d294b
	2178754  0000000000000f99 0000000000000003 00000000003cf654 0000000025c17d03
	2178755  ffff8801e8029e38 ffff8801e74fc000 00000002590dc5c4 ffffffff8163cdb0
	2178756 Call Trace:
	2178757  [] ? acpi_processor_ffh_cstate_enter+0x2d/0x2f
	2178758  [] acpi_idle_enter_bm+0x1b1/0x236
	2178759  [] ? disable_cpuidle+0x10/0x10
	2178760  [] cpuidle_enter+0x12/0x14
	2178761  [] cpuidle_wrap_enter+0x2f/0x6d
	2178762  [] cpuidle_enter_tk+0x10/0x12
	2178763  [] cpuidle_enter_state+0x12/0x3a
	2178764  [] cpuidle_idle_call+0xe8/0x161
	2178765  [] cpu_idle+0x5e/0xa4
	2178766  [] start_secondary+0x1a9/0x1ad
	2178767 Task dump for CPU 2:

In fact, the ACPI idle is based on the assumption of difference percpu
cstate structures that are necessary for the implementation to work
cprrectly.  A unique acpi_processor_cx is not sifficient by far.

This patch is just a quick fix re-introducing the percpu cstates.

If someone really wants to unify the ACPI cstates, please make sure
that the whole software infrastructure is changed and take hardware
as well as many different kinds of BIOS settings into account.

[rjw: Changelog]
Reported-by: LKP project 
Reported-by: Xie ChanglongX 
Tested-by: Yinghai Lu 
Signed-off-by: Alex Shi 
Signed-off-by: Rafael J. Wysocki

Merge branch 'misc' into release

2013-02-18T05:25:53+00:00

Conflicts:
	arch/x86/kernel/process.c

Signed-off-by: Len Brown

x86 idle: remove mwait_idle() and "idle=mwait" cmdline param

2013-02-10T08:03:41+00:00

mwait_idle() is a C1-only idle loop intended to be more efficient
than HLT, starting on Pentium-4 HT-enabled processors.

But mwait_idle() has been replaced by the more general
mwait_idle_with_hints(), which handles both C1 and deeper C-states.
ACPI processor_idle and intel_idle use only mwait_idle_with_hints(),
and no longer use mwait_idle().

Here we simplify the x86 native idle code by removing mwait_idle(),
and the "idle=mwait" bootparam used to invoke it.

Since Linux 3.0 there has been a boot-time warning when "idle=mwait"
was invoked saying it would be removed in 2012.  This removal
was also noted in the (now removed:-) feature-removal-schedule.txt.

After this change, kernels configured with
(CONFIG_ACPI=n && CONFIG_INTEL_IDLE=n) when run on hardware
that supports MWAIT will simply use HLT.  If MWAIT is desired
on those systems, cpuidle and the cpuidle drivers above
can be enabled.

Signed-off-by: Len Brown 
Cc: x86@kernel.org

ACPI / idle: remove usage of the statedata

2013-02-08T23:44:51+00:00

Len Brown sent a patch to remove this field in the intel_idle driver.
The other user of this field is the davinci cpuidle driver and a
patch has been sent to remove the usage of it.

This patch removes the last user of this field.

Signed-off-by: Daniel Lezcano 
Signed-off-by: Len Brown

ACPI / idle: pass the cpuidle_device parameter

2013-02-08T23:44:51+00:00

The cpuidle_device is retrieved in the function by using directly
the global variable. But the caller of this function already have
this device and it can be passed as a parameter. That is one small
step to encapsulate the code more.

Signed-off-by: Daniel Lezcano 
Signed-off-by: Len Brown