linux/drivers/base/power, branch v5.0

PM-runtime: Fix deadlock when canceling hrtimer

2019-02-21T09:29:00Z

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) Signed-off-by: Vincent Guittot [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki

PM-runtime: Fix deadlock with ktime_get()

2019-01-30T21:49:06Z

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 Signed-off-by: Vincent Guittot Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep'

2019-01-11T09:09:51Z

* 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

PM-runtime: Fix autosuspend_delay on 32bits arch

2019-01-10T09:55:52Z

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 Tested-by: Tony Lindgren Signed-off-by: Vincent Guittot Signed-off-by: Rafael J. Wysocki

PM-runtime: Fix 'jiffies' in comments after switch to hrtimers

2019-01-10T09:55:52Z

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 Signed-off-by: Rafael J. Wysocki

PM: sleep: call devfreq suspend/resume

2019-01-02T22:07:41Z

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 Reviewed-by: Chanwoo Choi Signed-off-by: Lukasz Luba Signed-off-by: Rafael J. Wysocki

Merge tag 'rtc-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

2019-01-01T21:24:31Z

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 ...

Merge branches 'pm-core', 'pm-qos', 'pm-domains' and 'pm-sleep'

2018-12-21T09:06:44Z

* 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

PM / Domains: remove define_genpd_open_function() and define_genpd_debugfs_fops()

2018-12-19T09:37:06Z

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 Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM-runtime: Switch autosuspend over to using hrtimers

2018-12-19T09:31:50Z

PM-runtime uses the timer infrastructure for autosuspend. This implies that the minimum time before autosuspending a device is in the range of 1 tick included to 2 ticks excluded -On arm64 this means between 4ms and 8ms with default jiffies configuration -And on arm, it is between 10ms and 20ms These values are quite high for embedded systems which sometimes want the duration to be in the range of 1 ms. It is possible to switch autosuspend over to using hrtimers to get finer granularity for short durations and take advantage of slack to retain some margins and get long timeouts with minimum wakeups. On an arm64 platform that uses 1ms for autosuspending timeout of its GPU, idle power is reduced by 10% with hrtimer. The latency impact on arm64 hikey octo cores is: - mark_last_busy: from 1.11 us to 1.25 us - rpm_suspend: from 15.54 us to 15.38 us [Only the code path of rpm_suspend() that starts hrtimer has been measured.] arm64 image (arm64 default defconfig) decreases by around 3KB with following details: $ size vmlinux-timer text data bss dec hex filename 12034646 6869268 386840 19290754 1265a82 vmlinux $ size vmlinux-hrtimer text data bss dec hex filename 12030550 6870164 387032 19287746 1264ec2 vmlinux The latency impact on arm 32bits snowball dual cores is : - mark_last_busy: from 0.31 us usec to 0.77 us - rpm_suspend: from 6.83 us to 6.67 usec The increase of the image for snowball platform that I used for testing performance impact, is neglictable (244B). $ size vmlinux-timer text data bss dec hex filename 7157961 2119580 264120 9541661 91981d build-ux500/vmlinux size vmlinux-hrtimer text data bss dec hex filename 7157773 2119884 264248 9541905 919911 vmlinux-hrtimer And arm 32bits image (multi_v7_defconfig) increases by around 1.7KB with following details: $ size vmlinux-timer text data bss dec hex filename 13304443 6803420 402768 20510631 138f7a7 vmlinux $ size vmlinux-hrtimer text data bss dec hex filename 13304299 6805276 402768 20512343 138fe57 vmlinux Signed-off-by: Vincent Guittot Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki