commit c998c07836f985b24361629dc98506ec7893e7a0 upstream.

Currently the 'registered' member of the cpuidle_device struct is set
to 1 during cpuidle_register_device. In this same function there are
checks to see if the device is already registered to prevent duplicate
calls to register the device, but this value is never set to 0 even on
unregister of the device. Because of this, any attempt to call
cpuidle_register_device after a call to cpuidle_unregister_device will
fail which shouldn't be the case.

To prevent this, set registered to 0 when the device is unregistered.

Fixes: c878a52d3c7c (cpuidle: Check if device is already registered)
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3836785a1bdcd6706c68ad46bf53adc0b057b310 upstream.

If there is a PM QoS latency limit and all of the sufficiently shallow
C-states are disabled, the cpuidle menu governor returns 0 which on
some systems is CPUIDLE_DRIVER_STATE_START and shouldn't be returned
if that C-state has been disabled.

Fix the issue by modifying the menu governor to return (-1) in such
situations.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[shilpab: Backport to 3.10.y
 - adjust context
 - add a check if 'next_state' is less than 0 in 'cpuidle_idle_call()',
   this ensures that we exit 'cpuidle_idle_call()' if governor->select()
   returns  negative value]
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d75e4af14e228bbe3f86e29bcecb8e6be98d4e04 upstream.

Thomas Schlichter reports the following issue on his Samsung NC20:

"The C-states C1 and C2 to the OS when connected to AC, and additionally
 provides the C3 C-state when disconnected from AC.  However, the number
 of C-states shown in sysfs is fixed to the number of C-states present
 at boot.
   If I boot with AC connected, I always only see the C-states up to C2
   even if I disconnect AC.

   The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count
   setting).  It removes the update of dev->state_count, but sysfs uses
   exactly this variable to show the C-states.

   The fix is to use drv->state_count in sysfs.  As this is currently the
   last user of dev->state_count, this variable can be completely removed."

Remove dev->state_count as per the above.

Reported-by: Thomas Schlichter <thomas.schlichter@web.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Following patch ports the cpuidle framework for powernv
platform and also implements a cpuidle back-end powernv
idle driver calling on to power7_nap and snooze idle states.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

smt-snooze-delay was designed to disable NAP state or delay the entry
to the NAP state prior to adoption of cpuidle framework. This
is per-cpu variable. With the coming of CPUIDLE framework,
states can be disabled on per-cpu basis using the cpuidle/enable
sysfs entry.

Also, with the coming of cpuidle driver each state's target residency
is per-driver unlike earlier which was per-device. Therefore,
the per-cpu sysfs smt-snooze-delay which decides the target residency
of the idle state on a particular cpu causes more confusion to the user
as we cannot have different smt-snooze-delay (target residency)
values for each cpu.

In the current code, smt-snooze-delay functionality is completely broken.
It makes sense to remove smt-snooze-delay from idle driver with the
coming of cpuidle framework.
However, sysfs files are retained as ppc64_util currently
utilises it. Once we fix ppc64_util, propose to clean
up the kernel code.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This patch removes the usage of MAX_IDLE_STATE macro
and dead code around it. The number of states
are determined at run time based on the cpuidle
state table selected on a given platform

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Currently cpuidle-pseries backend driver cannot be
built as a module due to dependencies wrt cpuidle framework.
This patch removes all the module related code in the driver.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This patch replaces the cpuidle driver and devices initialisation
calls with a single generic cpuidle_register() call
and also includes minor refactoring of the code around it.

Remove the cpu online check in snooze loop, as this code can
only locally run on a cpu only if it is online. Therefore,
this check is not required.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Move the file from arch specific pseries/processor_idle.c
to drivers/cpuidle/cpuidle-pseries.c
Make the relevant Makefile and Kconfig changes.
Also, introduce Kconfig.powerpc in drivers/cpuidle
for all powerpc cpuidle drivers.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Commit 60a66e370007e8535b7a561353b07b37deaf35ba changed the Calxeda
cpuidle driver to a platform driver, copying the __init tag from the
_init() to the newly used _probe() function. However, "probe should
not be __init." (Rob said ;-)
Remove the __init tag to fix a section mismatch in the Calxeda
cpuidle driver.

Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>