commit 1fad17fb1bbcd73159c2b992668a6957ecc5af8a upstream.

If wakeup_source_add() is called right after wakeup_source_remove()
for the same wakeup source, timer_setup() may be called for a
potentially scheduled timer which is incorrect.

To avoid that, move the wakeup source timer cancellation from
wakeup_source_drop() to wakeup_source_remove().

Moreover, make wakeup_source_remove() clear the timer function after
canceling the timer to let wakeup_source_not_registered() treat
unregistered wakeup sources in the same way as the ones that have
never been registered.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
[ rjw: Subject, changelog, merged two patches together ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When rpm_resume() desactivates the autosuspend timer, it should only
try to cancel hrtimer but not wait for the handler to finish, because
both rpm_resume() and pm_suspend_timer_fn() take the power.lock.

A deadlock is possible as follows:

CPU0                              CPU1
rpm_resume()
  spin_lock_irqsave
                                  pm_suspend_timer_fn()
                                    spin_lock_irqsave
  pm_runtime_deactivate_timer()
    hrtimer_cancel()

It is sufficient to call hrtimer_try_to_cancel() from
pm_runtime_deactivate_timer(), because dev->power.timer_expires
reset to 0 by it, so use that function instead of hrtimer_cancel().

Fixes: 8234f6734c5d ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Sunzhaosheng Sun(Zhaosheng) <sunzhaosheng@hisilicon.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

A deadlock has been seen when swicthing clocksources which use
PM-runtime.  The call path is:

change_clocksource
    ...
    write_seqcount_begin
    ...
    timekeeping_update
        ...
        sh_cmt_clocksource_enable
            ...
            rpm_resume
                pm_runtime_mark_last_busy
                    ktime_get
                        do
                            read_seqcount_begin
                        while read_seqcount_retry
    ....
    write_seqcount_end

Although we should be safe because we haven't yet changed the
clocksource at that time, we can't do that because of seqcount
protection.

Use ktime_get_mono_fast_ns() instead which is lock safe for such
cases.

With ktime_get_mono_fast_ns, the timestamp is not guaranteed to be
monotonic across an update and as a result can goes backward.
According to update_fast_timekeeper() description: "In the worst
case, this can result is a slightly wrong timestamp (a few
nanoseconds)". For PM-runtime autosuspend, this means only that
the suspend decision may be slightly suboptimal.

Fixes: 8234f6734c5d ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

* pm-cpuidle:
  doc: trace: fix reference to cpuidle documentation file
  cpuidle / Documentation: Update cpuidle MAINTAINERS entry

* pm-cpufreq:
  cpufreq: scmi: Fix frequency invariance in slow path
  cpufreq: check if policy is inactive early in __cpufreq_get()
  cpufreq: scpi/scmi: Fix freeing of dynamic OPPs
  cpufreq / Documentation: Update cpufreq MAINTAINERS entry

* pm-sleep:
  PM: sleep: call devfreq suspend/resume

Cast autosuspend_delay to u64 to make sure that the full computation
of 'expires' or slack will be done in u64, even on 32bits arch.

Otherwise, any delay greater than 2^31 nsec can overflow if signed
32bits is used when converting delay from msec to nsec.

Fixes: 8234f6734c5d (PM-runtime: Switch autosuspend over to using hrtimers)
Reported-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM-runtime now uses the hrtimers infrastructure for autosuspend, however
comments still reference 'jiffies'.

Fixes: 8234f6734c5d (PM-runtime: Switch autosuspend over to using hrtimers)
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Devfreq framework supports suspend of its devices.
Call the the devfreq interface and allow devfreq devices
preserve/restore their states during suspend/resume.

Suggested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull RTC updates from Alexandre Belloni:
 "Subsystem:
   - new %ptR printk format
   - rename core files
   - allow registration of multiple nvmem devices

  New driver:
   - i.MX system controller RTC

  Driver updates:
   - abx80x: handle voltage ioctls, correct binding doc
   - m41t80: correct month in alarm reads
   - pcf85363: add pcf85263 support
   - pcf8523: properly handle battery low flag
   - s3c: limit alarm to one year in the future as ALMYEAR is broken
   - sun6i: rework clock output binding"

* tag 'rtc-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (54 commits)
  rtc: rename core files
  rtc: nvmem: fix possible use after free
  rtc: add i.MX system controller RTC support
  dt-bindings: fsl: scu: add rtc binding
  rtc: pcf2123: Add Microcrystal rv2123
  rtc: class: reimplement devm_rtc_device_register
  rtc: enforce rtc_timer_init private_data type
  rtc: abx80x: Implement RTC_VL_READ,CLR ioctls
  rtc: pcf85363: Add support for NXP pcf85263 rtc
  dt-bindings: rtc: pcf85363: Document pcf85263 real-time clock
  rtc: pcf8523: don't return invalid date when battery is low
  dt-bindings: rtc: use a generic node name for ds1307
  PM: Switch to use %ptR
  m68k/mac: Switch to use %ptR
  Input: hp_sdc_rtc - Switch to use %ptR
  rtc: tegra: Switch to use %ptR
  rtc: s5m: Switch to use %ptR
  rtc: s3c: Switch to use %ptR
  rtc: rx8025: Switch to use %ptR
  rtc: rx6110: Switch to use %ptR
  ...

* pm-core:
  PM-runtime: Switch autosuspend over to using hrtimers

* pm-qos:
  PM / QoS: Change to use DEFINE_SHOW_ATTRIBUTE macro

* pm-domains:
  PM / Domains: remove define_genpd_open_function() and define_genpd_debugfs_fops()

* pm-sleep:
  PM / sleep: convert to DEFINE_SHOW_ATTRIBUTE

We already have the DEFINE_SHOW_ATTRIBUTE, There is no need to define
such a macro, so remove define_genpd_open_function and
define_genpd_debugfs_fops.

Convert them to DEFINE_SHOW_ATTRIBUTE.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>