linux-stable.git/drivers/cpuidle/driver.c, branch linux-3.16.y Linux kernel stable tree cpuidle: Do not unset the driver if it is there already 2020-02-11T20:03:20+00:00 Zhenzhong Duan zhenzhong.duan@oracle.com 2019-10-23T01:57:14+00:00 6171eb0871c37d73620fdd37889bab7bf0883b23 commit 918c1fe9fbbe46fcf56837ff21f0ef96424e8b29 upstream. Fix __cpuidle_set_driver() to check if any of the CPUs in the mask has a driver different from drv already and, if so, return -EBUSY before updating any cpuidle_drivers per-CPU pointers. Fixes: 82467a5a885d ("cpuidle: simplify multiple driver support") Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 918c1fe9fbbe46fcf56837ff21f0ef96424e8b29 upstream.

Fix __cpuidle_set_driver() to check if any of the CPUs in the mask has
a driver different from drv already and, if so, return -EBUSY before
updating any cpuidle_drivers per-CPU pointers.

Fixes: 82467a5a885d ("cpuidle: simplify multiple driver support")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
cpuidle: Set polling in poll_idle 2014-06-05T10:09:49+00:00 Andy Lutomirski luto@amacapital.net 2014-06-04T17:31:14+00:00 84c407084137d4e491b07ea5ff8665d19106a5ac poll_idle is the archetypal polling idle loop; tell the core idle code about it. This avoids pointless IPIs when all of the other cpuidle states are disabled. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: nicolas.pitre@linaro.org Cc: umgwanakikbuti@gmail.com Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org Link: http://lkml.kernel.org/r/c65ce49615d338bae8fb79df5daffab19353c900.1401902905.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org> 
poll_idle is the archetypal polling idle loop; tell the core idle
code about it.

This avoids pointless IPIs when all of the other cpuidle states are
disabled.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: nicolas.pitre@linaro.org
Cc: umgwanakikbuti@gmail.com
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Link: http://lkml.kernel.org/r/c65ce49615d338bae8fb79df5daffab19353c900.1401902905.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
cpuidle: poll state can measure residency 2014-03-07T11:55:17+00:00 tuukka.tikkanen@linaro.org tuukka.tikkanen@linaro.org 2014-02-24T06:29:37+00:00 4b2f0b033a294e6c19d57c5d0a66c000f6299559 For some platforms, a poll state is inserted in the cpuidle driver states. The flags for the state do not indicate that timekeeping is not affected. As the state does not do anything apart from calling cpu_relax(), the times returned by ktime_get should remain valid. Add the missing flag. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
For some platforms, a poll state is inserted in the cpuidle driver states.
The flags for the state do not indicate that timekeeping is not affected.
As the state does not do anything apart from calling cpu_relax(), the
times returned by ktime_get should remain valid. Add the missing flag.

Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: don't call poll_idle_init() for every cpu 2013-10-30T00:21:23+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-10-03T15:56:54+00:00 d7c7f103262bc2248548ed0e113e916e843c4eeb poll_idle_init() just initializes drv->states[0] and so that is required to be done only once for each driver. Currently, it is called from cpuidle_enable_device() which is called for every CPU that the driver supports. That is not required, so move it to a better place and call it from __cpuidle_register_driver() so that the initialization is carried out only once. Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
poll_idle_init() just initializes drv->states[0] and so that is
required to be done only once for each driver.  Currently, it is
called from cpuidle_enable_device() which is called for every CPU
that the driver supports.  That is not required, so move it to a
better place and call it from __cpuidle_register_driver() so that
the initialization is carried out only once.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: call cpuidle_get_driver() from after taking cpuidle_driver_lock 2013-10-30T00:21:23+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-10-03T15:56:50+00:00 0d09d3125642ac1f02937e577819dbc515291d93 There are a few cpuidle_get_driver() calls that aren't made under cpuidle_driver_lock which is incorrect. Fix them by calling cpuidle_get_driver() after taking cpuidle_driver_lock. Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
There are a few cpuidle_get_driver() calls that aren't made under
cpuidle_driver_lock which is incorrect.

Fix them by calling cpuidle_get_driver() after taking cpuidle_driver_lock.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: rearrange code in __cpuidle_driver_init() 2013-10-30T00:21:22+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-10-03T15:56:45+00:00 b171a85648e7055c6680c259a9a87806a56a24c3 This is trivial patch that just reorders a few statements in __cpuidle_driver_init() routine so that we don't need both 'continue' and 'break' in the for loop. Functionally it shouldn't change anything. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
This is trivial patch that just reorders a few statements in
__cpuidle_driver_init() routine so that we don't need both 'continue'
and 'break' in the for loop. Functionally it shouldn't change anything.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: make __cpuidle_driver_init() return void 2013-10-30T00:21:22+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-10-03T15:56:44+00:00 e437f3e37369606bf1a340e0504554d6530abc51 The only value returned by __cpuidle_driver_init() is 0, so it very well may be a void function. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
The only value returned by __cpuidle_driver_init() is 0, so it
very well may be a void function.

[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: Fix comments in cpuidle core 2013-10-30T00:21:21+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-10-03T15:56:41+00:00 caf4a36e818ba8df4e002b7dfa4eff5b8384dda0 Some comments in cpuidle core files contain trivial mistakes. This patch fixes them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Some comments in cpuidle core files contain trivial mistakes.
This patch fixes them.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: Check the result of cpuidle_get_driver() against NULL 2013-08-30T19:53:41+00:00 Daniel Fu danifu@nvidia.com 2013-08-30T11:48:22+00:00 3b9c10e98021e1f92e6f8c7ce1778b86ba68db10 If the current CPU has no cpuidle driver, drv will be NULL in cpuidle_driver_ref(). Check if that is the case before trying to bump up the driver's refcount to prevent the kernel from crashing. [rjw: Subject and changelog] Signed-off-by: Daniel Fu <danifu@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
If the current CPU has no cpuidle driver, drv will be NULL in
cpuidle_driver_ref().  Check if that is the case before trying
to bump up the driver's refcount to prevent the kernel from
crashing.

[rjw: Subject and changelog]
Signed-off-by: Daniel Fu <danifu@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: Comment the driver's framework code 2013-06-11T12:18:33+00:00 Daniel Lezcano daniel.lezcano@linaro.org 2013-06-07T21:53:10+00:00 6d19cb93d60a5403753756c502699751116c954c Add kerneldoc (and other) comments to the cpuidle driver's framework code. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Add kerneldoc (and other) comments to the cpuidle driver's framework
code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>