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Merge tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/ke…
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Pull power management and ACPI updates from Rafael Wysocki:
 "This time the total number of ACPI commits is slightly greater than
  the number of cpufreq commits, but Viresh Kumar (who works on cpufreq)
  remains the most active patch submitter.

  To me, the most significant change is the addition of offline/online
  device operations to the driver core (with the Greg's blessing) and
  the related modifications of the ACPI core hotplug code.  Next are the
  freezer updates from Colin Cross that should make the freezing of
  tasks a bit less heavy weight.

  We also have a couple of regression fixes, a number of fixes for
  issues that have not been identified as regressions, two new drivers
  and a bunch of cleanups all over.

  Highlights:

   - Hotplug changes to support graceful hot-removal failures.

     It sometimes is necessary to fail device hot-removal operations
     gracefully if they cannot be carried out completely.  For example,
     if memory from a memory module being hot-removed has been allocated
     for the kernel's own use and cannot be moved elsewhere, it's
     desirable to fail the hot-removal operation in a graceful way
     rather than to crash the kernel, but currenty a success or a kernel
     crash are the only possible outcomes of an attempted memory
     hot-removal.  Needless to say, that is not a very attractive
     alternative and it had to be addressed.

     However, in order to make it work for memory, I first had to make
     it work for CPUs and for this purpose I needed to modify the ACPI
     processor driver.  It's been split into two parts, a resident one
     handling the low-level initialization/cleanup and a modular one
     playing the actual driver's role (but it binds to the CPU system
     device objects rather than to the ACPI device objects representing
     processors).  That's been sort of like a live brain surgery on a
     patient who's riding a bike.

     So this is a little scary, but since we found and fixed a couple of
     regressions it caused to happen during the early linux-next testing
     (a month ago), nobody has complained.

     As a bonus we remove some duplicated ACPI hotplug code, because the
     ACPI-based CPU hotplug is now going to use the common ACPI hotplug
     code.

   - Lighter weight freezing of tasks.

     These changes from Colin Cross and Mandeep Singh Baines are
     targeted at making the freezing of tasks a bit less heavy weight
     operation.  They reduce the number of tasks woken up every time
     during the freezing, by using the observation that the freezer
     simply doesn't need to wake up some of them and wait for them all
     to call refrigerator().  The time needed for the freezer to decide
     to report a failure is reduced too.

     Also reintroduced is the check causing a lockdep warining to
     trigger when try_to_freeze() is called with locks held (which is
     generally unsafe and shouldn't happen).

   - cpufreq updates

     First off, a commit from Srivatsa S Bhat fixes a resume regression
     introduced during the 3.10 cycle causing some cpufreq sysfs
     attributes to return wrong values to user space after resume.  The
     fix is kind of fresh, but also it's pretty obvious once Srivatsa
     has identified the root cause.

     Second, we have a new freqdomain_cpus sysfs attribute for the
     acpi-cpufreq driver to provide information previously available via
     related_cpus.  From Lan Tianyu.

     Finally, we fix a number of issues, mostly related to the
     CPUFREQ_POSTCHANGE notifier and cpufreq Kconfig options and clean
     up some code.  The majority of changes from Viresh Kumar with bits
     from Jacob Shin, Heiko Stübner, Xiaoguang Chen, Ezequiel Garcia,
     Arnd Bergmann, and Tang Yuantian.

   - ACPICA update

     A usual bunch of updates from the ACPICA upstream.

     During the 3.4 cycle we introduced support for ACPI 5 extended
     sleep registers, but they are only supposed to be used if the
     HW-reduced mode bit is set in the FADT flags and the code attempted
     to use them without checking that bit.  That caused suspend/resume
     regressions to happen on some systems.  Fix from Lv Zheng causes
     those registers to be used only if the HW-reduced mode bit is set.

     Apart from this some other ACPICA bugs are fixed and code cleanups
     are made by Bob Moore, Tomasz Nowicki, Lv Zheng, Chao Guan, and
     Zhang Rui.

   - cpuidle updates

     New driver for Xilinx Zynq processors is added by Michal Simek.

     Multidriver support simplification, addition of some missing
     kerneldoc comments and Kconfig-related fixes come from Daniel
     Lezcano.

   - ACPI power management updates

     Changes to make suspend/resume work correctly in Xen guests from
     Konrad Rzeszutek Wilk, sparse warning fix from Fengguang Wu and
     cleanups and fixes of the ACPI device power state selection
     routine.

   - ACPI documentation updates

     Some previously missing pieces of ACPI documentation are added by
     Lv Zheng and Aaron Lu (hopefully, that will help people to
     uderstand how the ACPI subsystem works) and one outdated doc is
     updated by Hanjun Guo.

   - Assorted ACPI updates

     We finally nailed down the IA-64 issue that was the reason for
     reverting commit 9f29ab1 ("ACPI / scan: do not match drivers
     against objects having scan handlers"), so we can fix it and move
     the ACPI scan handler check added to the ACPI video driver back to
     the core.

     A mechanism for adding CMOS RTC address space handlers is
     introduced by Lan Tianyu to allow some EC-related breakage to be
     fixed on some systems.

     A spec-compliant implementation of acpi_os_get_timer() is added by
     Mika Westerberg.

     The evaluation of _STA is added to do_acpi_find_child() to avoid
     situations in which a pointer to a disabled device object is
     returned instead of an enabled one with the same _ADR value.  From
     Jeff Wu.

     Intel BayTrail PCH (Platform Controller Hub) support is added to
     the ACPI driver for Intel Low-Power Subsystems (LPSS) and that
     driver is modified to work around a couple of known BIOS issues.
     Changes from Mika Westerberg and Heikki Krogerus.

     The EC driver is fixed by Vasiliy Kulikov to use get_user() and
     put_user() instead of dereferencing user space pointers blindly.

     Code cleanups are made by Bjorn Helgaas, Nicholas Mazzuca and Toshi
     Kani.

   - Assorted power management updates

     The "runtime idle" helper routine is changed to take the return
     values of the callbacks executed by it into account and to call
     rpm_suspend() if they return 0, which allows us to reduce the
     overall code bloat a bit (by dropping some code that's not
     necessary any more after that modification).

     The runtime PM documentation is updated by Alan Stern (to reflect
     the "runtime idle" behavior change).

     New trace points for PM QoS are added by Sahara
     (<[email protected]>).

     PM QoS documentation is updated by Lan Tianyu.

     Code cleanups are made and minor issues are addressed by Bernie
     Thompson, Bjorn Helgaas, Julius Werner, and Shuah Khan.

   - devfreq updates

     New driver for the Exynos5-bus device from Abhilash Kesavan.

     Minor cleanups, fixes and MAINTAINERS update from MyungJoo Ham,
     Abhilash Kesavan, Paul Bolle, Rajagopal Venkat, and Wei Yongjun.

   - OMAP power management updates

     Adaptive Voltage Scaling (AVS) SmartReflex voltage control driver
     updates from Andrii Tseglytskyi and Nishanth Menon."

* tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (162 commits)
  cpufreq: Fix cpufreq regression after suspend/resume
  ACPI / PM: Fix possible NULL pointer deref in acpi_pm_device_sleep_state()
  PM / Sleep: Warn about system time after resume with pm_trace
  cpufreq: don't leave stale policy pointer in cdbs->cur_policy
  acpi-cpufreq: Add new sysfs attribute freqdomain_cpus
  cpufreq: make sure frequency transitions are serialized
  ACPI: implement acpi_os_get_timer() according the spec
  ACPI / EC: Add HP Folio 13 to ec_dmi_table in order to skip DSDT scan
  ACPI: Add CMOS RTC Operation Region handler support
  ACPI / processor: Drop unused variable from processor_perflib.c
  cpufreq: tegra: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: s3c64xx: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: omap: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: imx6q: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: exynos: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: dbx500: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: davinci: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: arm-big-little: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: powernow-k8: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: pcc: call CPUFREQ_POSTCHANGE notfier in error cases
  ...
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torvalds committed Jul 3, 2013
2 parents d414153 + 2c843bd commit f991fae
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58 changes: 58 additions & 0 deletions Documentation/ABI/testing/sysfs-bus-acpi
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What: /sys/bus/acpi/devices/.../path
Date: December 2006
Contact: Rafael J. Wysocki <[email protected]>
Description:
This attribute indicates the full path of ACPI namespace
object associated with the device object. For example,
\_SB_.PCI0.
This file is not present for device objects representing
fixed ACPI hardware features (like power and sleep
buttons).

What: /sys/bus/acpi/devices/.../modalias
Date: July 2007
Contact: Rafael J. Wysocki <[email protected]>
Description:
This attribute indicates the PNP IDs of the device object.
That is acpi:HHHHHHHH:[CCCCCCC:]. Where each HHHHHHHH or
CCCCCCCC contains device object's PNPID (_HID or _CID).

What: /sys/bus/acpi/devices/.../hid
Date: April 2005
Contact: Rafael J. Wysocki <[email protected]>
Description:
This attribute indicates the hardware ID (_HID) of the
device object. For example, PNP0103.
This file is present for device objects having the _HID
control method.

What: /sys/bus/acpi/devices/.../description
Date: October 2012
Contact: Rafael J. Wysocki <[email protected]>
Description:
This attribute contains the output of the device object's
_STR control method, if present.

What: /sys/bus/acpi/devices/.../adr
Date: October 2012
Contact: Rafael J. Wysocki <[email protected]>
Description:
This attribute contains the output of the device object's
_ADR control method, which is present for ACPI device
objects representing devices having standard enumeration
algorithms, such as PCI.

What: /sys/bus/acpi/devices/.../uid
Date: October 2012
Contact: Rafael J. Wysocki <[email protected]>
Description:
This attribute contains the output of the device object's
_UID control method, if present.

What: /sys/bus/acpi/devices/.../eject
Date: December 2006
Contact: Rafael J. Wysocki <[email protected]>
Description:
Writing 1 to this attribute will trigger hot removal of
this device object. This file exists for every device
object that has _EJ0 method.
20 changes: 20 additions & 0 deletions Documentation/ABI/testing/sysfs-class-devfreq
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Expand Up @@ -78,3 +78,23 @@ Contact: Nishanth Menon <[email protected]>
Description:
The /sys/class/devfreq/.../available_governors shows
currently available governors in the system.

What: /sys/class/devfreq/.../min_freq
Date: January 2013
Contact: MyungJoo Ham <[email protected]>
Description:
The /sys/class/devfreq/.../min_freq shows and stores
the minimum frequency requested by users. It is 0 if
the user does not care. min_freq overrides the
frequency requested by governors.

What: /sys/class/devfreq/.../max_freq
Date: January 2013
Contact: MyungJoo Ham <[email protected]>
Description:
The /sys/class/devfreq/.../max_freq shows and stores
the maximum frequency requested by users. It is 0 if
the user does not care. max_freq overrides the
frequency requested by governors and min_freq.
The max_freq overrides min_freq because max_freq may be
used to throttle devices to avoid overheating.
20 changes: 20 additions & 0 deletions Documentation/ABI/testing/sysfs-devices-online
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What: /sys/devices/.../online
Date: April 2013
Contact: Rafael J. Wysocki <[email protected]>
Description:
The /sys/devices/.../online attribute is only present for
devices whose bus types provide .online() and .offline()
callbacks. The number read from it (0 or 1) reflects the value
of the device's 'offline' field. If that number is 1 and '0'
(or 'n', or 'N') is written to this file, the device bus type's
.offline() callback is executed for the device and (if
successful) its 'offline' field is updated accordingly. In
turn, if that number is 0 and '1' (or 'y', or 'Y') is written to
this file, the device bus type's .online() callback is executed
for the device and (if successful) its 'offline' field is
updated as appropriate.

After a successful execution of the bus type's .offline()
callback the device cannot be used for any purpose until either
it is removed (i.e. device_del() is called for it), or its bus
type's .online() is exeucted successfully.
2 changes: 1 addition & 1 deletion Documentation/ABI/testing/sysfs-devices-sun
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@@ -1,4 +1,4 @@
Whatt: /sys/devices/.../sun
What: /sys/devices/.../sun
Date: October 2012
Contact: Yasuaki Ishimatsu <[email protected]>
Description:
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15 changes: 15 additions & 0 deletions Documentation/ABI/testing/sysfs-devices-system-cpu
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Expand Up @@ -144,6 +144,21 @@ Description: Discover and change clock speed of CPUs
to learn how to control the knobs.


What: /sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus
Date: June 2013
Contact: [email protected]
Description: Discover CPUs in the same CPU frequency coordination domain

freqdomain_cpus is the list of CPUs (online+offline) that share
the same clock/freq domain (possibly at the hardware level).
That information may be hidden from the cpufreq core and the
value of related_cpus may be different from freqdomain_cpus. This
attribute is useful for user space DVFS controllers to get better
power/performance results for platforms using acpi-cpufreq.

This file is only present if the acpi-cpufreq driver is in use.


What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
Date: August 2008
KernelVersion: 2.6.27
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10 changes: 10 additions & 0 deletions Documentation/ABI/testing/sysfs-firmware-acpi
Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,16 @@ Description:
or 0 (unset). Attempts to write any other values to it will
cause -EINVAL to be returned.

What: /sys/firmware/acpi/hotplug/force_remove
Date: May 2013
Contact: Rafael J. Wysocki <[email protected]>
Description:
The number in this file (0 or 1) determines whether (1) or not
(0) the ACPI subsystem will allow devices to be hot-removed even
if they cannot be put offline gracefully (from the kernel's
viewpoint). That number can be changed by writing a boolean
value to this file.

What: /sys/firmware/acpi/interrupts/
Date: February 2008
Contact: Len Brown <[email protected]>
Expand Down
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