ACPI battery: only refresh the sysfs files when pertinent information changes

We only need to regenerate the sysfs files when the capacity units
change, avoid the update otherwise.

The origin of this issue is dates way back to 2.6.38:
da8aeb92d4853f37e281f11fddf61f9c7d84c3cd
(ACPI / Battery: Update information on info notification and resume)

cc: <stable@vger.kernel.org>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Tested-by: Ralf Jung <post@ralfj.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Merge branch 'battery' into next
ACPI: Ignore invalid _PSS entries, but use valid ones

The EliteBook 8560W has non-initialized entries in its _PSS ACPI
table. Instead of bailing out when the first non-initialized entry is
found, ignore it and use only  the valid entries. Only bail out if there
is no valid entry at all.

[v3: Fixes suggested by Konrad]

Signed-off-by: Marco Aurelio da Costa <costa@gamic.com>
Signed-off-by: Len Brown <len.brown@intel.com>
acpi_video: fix leaking PCI references

Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
acpi_video: Intel video is not always i915

Stop it poking at random registers on the i740 cards that may be out there
still.

As per Matthew's feedback remove the conditional checks and never enable the
opregion handling unless an appropriate driver has been loaded.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
gma500: don't register the ACPI video bus

We are not yet ready for this and it makes a mess on some devices.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
cpuidle: refactor out cpuidle_enter_state

Split the code to enter a state and update the stats into a helper
function, cpuidle_enter_state, and export it.  This function will
be called by the coupled state code to handle entering the safe
state and the final coupled state.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Len Brown <len.brown@intel.com>
cpuidle: fix error handling in __cpuidle_register_device

Fix the error handling in __cpuidle_register_device to include
the missing list_del.  Move it to a label, which will simplify
the error handling when coupled states are added.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Len Brown <len.brown@intel.com>
cpuidle: add support for states that affect multiple cpus

On some ARM SMP SoCs (OMAP4460, Tegra 2, and probably more), the
cpus cannot be independently powered down, either due to
sequencing restrictions (on Tegra 2, cpu 0 must be the last to
power down), or due to HW bugs (on OMAP4460, a cpu powering up
will corrupt the gic state unless the other cpu runs a work
around).  Each cpu has a power state that it can enter without
coordinating with the other cpu (usually Wait For Interrupt, or
WFI), and one or more "coupled" power states that affect blocks
shared between the cpus (L2 cache, interrupt controller, and
sometimes the whole SoC).  Entering a coupled power state must
be tightly controlled on both cpus.

The easiest solution to implementing coupled cpu power states is
to hotplug all but one cpu whenever possible, usually using a
cpufreq governor that looks at cpu load to determine when to
enable the secondary cpus.  This causes problems, as hotplug is an
expensive operation, so the number of hotplug transitions must be
minimized, leading to very slow response to loads, often on the
order of seconds.

This file implements an alternative solution, where each cpu will
wait in the WFI state until all cpus are ready to enter a coupled
state, at which point the coupled state function will be called
on all cpus at approximately the same time.

Once all cpus are ready to enter idle, they are woken by an smp
cross call.  At this point, there is a chance that one of the
cpus will find work to do, and choose not to enter idle.  A
final pass is needed to guarantee that all cpus will call the
power state enter function at the same time.  During this pass,
each cpu will increment the ready counter, and continue once the
ready counter matches the number of online coupled cpus.  If any
cpu exits idle, the other cpus will decrement their counter and
retry.

To use coupled cpuidle states, a cpuidle driver must:

   Set struct cpuidle_device.coupled_cpus to the mask of all
   coupled cpus, usually the same as cpu_possible_mask if all cpus
   are part of the same cluster.  The coupled_cpus mask must be
   set in the struct cpuidle_device for each cpu.

   Set struct cpuidle_device.safe_state to a state that is not a
   coupled state.  This is usually WFI.

   Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each
   state that affects multiple cpus.

   Provide a struct cpuidle_state.enter function for each state
   that affects multiple cpus.  This function is guaranteed to be
   called on all cpus at approximately the same time.  The driver
   should ensure that the cpus all abort together if any cpu tries
   to abort once the function is called.

Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Trinabh Gupta <g.trinabh@gmail.com>
Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Len Brown <len.brown@intel.com>
cpuidle: coupled: add parallel barrier function

Adds cpuidle_coupled_parallel_barrier, which can be used by coupled
cpuidle state enter functions to handle resynchronization after
determining if any cpu needs to abort.  The normal use case will
be:

static bool abort_flag;
static atomic_t abort_barrier;

int arch_cpuidle_enter(struct cpuidle_device *dev, ...)
{
	if (arch_turn_off_irq_controller()) {
	   	/* returns an error if an irq is pending and would be lost
		   if idle continued and turned off power */
		abort_flag = true;
	}

	cpuidle_coupled_parallel_barrier(dev, &abort_barrier);

	if (abort_flag) {
	   	/* One of the cpus didn't turn off it's irq controller */
	   	arch_turn_on_irq_controller();
		return -EINTR;
	}

	/* continue with idle */
	...
}

This will cause all cpus to abort idle together if one of them needs
to abort.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Merge branch 'video' into next
Merge branch 'cpuidle' into next
ACPI-Thermal: Make Thermal trip points writeable

Some of the thermal drivers using the Generic Thermal Framework
require (all/some) trip points to be writeable. This patch makes
the trip point temperatures writeable on a per-trip point basis,
and modifies the required function call in thermal.c. This patch
also updates the Documentation to reflect the new change.

Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI-Thermal: Add Hysteresis attributes

The Linux Thermal Framework does not support hysteresis
attributes. Most thermal sensors, today, have a
hysteresis value associated with trip points.

This patch adds hysteresis attributes on a per-trip-point
basis, to the Thermal Framework. These attributes are
optionally writable.

Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Merge branch 'thermal' into next
Merge branch 'pss-workaround' into next