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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-13 19:43:50 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-13 19:43:50 -0800 |
commit | bd2cd7d5a8f83ddc761025f42a3ca8e56351a6cc (patch) | |
tree | 6ea70f09f32544f895020e198dac632145332cc2 /drivers/base/power/domain_governor.c | |
parent | b29c6ef7bb1257853c1e31616d84f55e561cf631 (diff) | |
parent | 990a848d537e4da966907c8ccec95bc568f2911c (diff) |
Merge tag 'pm-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"There are no real big ticket items here this time.
The most noticeable change is probably the relocation of the OPP
(Operating Performance Points) framework to its own directory under
drivers/ as it has grown big enough for that. Also Viresh is now going
to maintain it and send pull requests for it to me, so you will see
this change in the git history going forward (but still not right
now).
Another noticeable set of changes is the modifications of the PM core,
the PCI subsystem and the ACPI PM domain to allow of more integration
between system-wide suspend/resume and runtime PM. For now it's just a
way to avoid resuming devices from runtime suspend unnecessarily
during system suspend (if the driver sets a flag to indicate its
readiness for that) and in the works is an analogous mechanism to
allow devices to stay suspended after system resume.
In addition to that, we have some changes related to supporting
frequency-invariant CPU utilization metrics in the scheduler and in
the schedutil cpufreq governor on ARM and changes to add support for
device performance states to the generic power domains (genpd)
framework.
The rest is mostly fixes and cleanups of various sorts.
Specifics:
- Relocate the OPP (Operating Performance Points) framework to its
own directory under drivers/ and add support for power domain
performance states to it (Viresh Kumar).
- Modify the PM core, the PCI bus type and the ACPI PM domain to
support power management driver flags allowing device drivers to
specify their capabilities and preferences regarding the handling
of devices with enabled runtime PM during system suspend/resume and
clean up that code somewhat (Rafael Wysocki, Ulf Hansson).
- Add frequency-invariant accounting support to the task scheduler on
ARM and ARM64 (Dietmar Eggemann).
- Fix PM QoS device resume latency framework to prevent "no
restriction" requests from overriding requests with specific
requirements and drop the confusing PM_QOS_FLAG_REMOTE_WAKEUP
device PM QoS flag (Rafael Wysocki).
- Drop legacy class suspend/resume operations from the PM core and
drop legacy bus type suspend and resume callbacks from ARM/locomo
(Rafael Wysocki).
- Add min/max frequency support to devfreq and clean it up somewhat
(Chanwoo Choi).
- Rework wakeup support in the generic power domains (genpd)
framework and update some of its users accordingly (Geert
Uytterhoeven).
- Convert timers in the PM core to use timer_setup() (Kees Cook).
- Add support for exposing the SLP_S0 (Low Power S0 Idle) residency
counter based on the LPIT ACPI table on Intel platforms (Srinivas
Pandruvada).
- Add per-CPU PM QoS resume latency support to the ladder cpuidle
governor (Ramesh Thomas).
- Fix a deadlock between the wakeup notify handler and the notifier
removal in the ACPI core (Ville Syrjälä).
- Fix a cpufreq schedutil governor issue causing it to use stale
cached frequency values sometimes (Viresh Kumar).
- Fix an issue in the system suspend core support code causing wakeup
events detection to fail in some cases (Rajat Jain).
- Fix the generic power domains (genpd) framework to prevent the PM
core from using the direct-complete optimization with it as that is
guaranteed to fail (Ulf Hansson).
- Fix a minor issue in the cpuidle core and clean it up a bit (Gaurav
Jindal, Nicholas Piggin).
- Fix and clean up the intel_idle and ARM cpuidle drivers (Jason
Baron, Len Brown, Leo Yan).
- Fix a couple of minor issues in the OPP framework and clean it up
(Arvind Yadav, Fabio Estevam, Sudeep Holla, Tobias Jordan).
- Fix and clean up some cpufreq drivers and fix a minor issue in the
cpufreq statistics code (Arvind Yadav, Bhumika Goyal, Fabio
Estevam, Gautham Shenoy, Gustavo Silva, Marek Szyprowski, Masahiro
Yamada, Robert Jarzmik, Zumeng Chen).
- Fix minor issues in the system suspend and hibernation core, in
power management documentation and in the AVS (Adaptive Voltage
Scaling) framework (Helge Deller, Himanshu Jha, Joe Perches, Rafael
Wysocki).
- Fix some issues in the cpupower utility and document that Shuah
Khan is going to maintain it going forward (Prarit Bhargava, Shuah
Khan)"
* tag 'pm-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (88 commits)
tools/power/cpupower: add libcpupower.so.0.0.1 to .gitignore
tools/power/cpupower: Add 64 bit library detection
intel_idle: Graceful probe failure when MWAIT is disabled
cpufreq: schedutil: Reset cached_raw_freq when not in sync with next_freq
freezer: Fix typo in freezable_schedule_timeout() comment
PM / s2idle: Clear the events_check_enabled flag
cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZE
cpufreq: arm_big_little: make cpufreq_arm_bL_ops structures const
cpufreq: arm_big_little: make function arguments and structure pointer const
cpuidle: Avoid assignment in if () argument
cpuidle: Clean up cpuidle_enable_device() error handling a bit
ACPI / PM: Fix acpi_pm_notifier_lock vs flush_workqueue() deadlock
PM / Domains: Fix genpd to deal with drivers returning 1 from ->prepare()
cpuidle: ladder: Add per CPU PM QoS resume latency support
PM / QoS: Fix device resume latency framework
PM / domains: Rework governor code to be more consistent
PM / Domains: Remove gpd_dev_ops.active_wakeup() callback
soc: rockchip: power-domain: Use GENPD_FLAG_ACTIVE_WAKEUP
soc: mediatek: Use GENPD_FLAG_ACTIVE_WAKEUP
ARM: shmobile: pm-rmobile: Use GENPD_FLAG_ACTIVE_WAKEUP
...
Diffstat (limited to 'drivers/base/power/domain_governor.c')
-rw-r--r-- | drivers/base/power/domain_governor.c | 73 |
1 files changed, 46 insertions, 27 deletions
diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index 281f949c5ffe..99896fbf18e4 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -14,23 +14,29 @@ static int dev_update_qos_constraint(struct device *dev, void *data) { s64 *constraint_ns_p = data; - s32 constraint_ns = -1; + s64 constraint_ns; - if (dev->power.subsys_data && dev->power.subsys_data->domain_data) + if (dev->power.subsys_data && dev->power.subsys_data->domain_data) { + /* + * Only take suspend-time QoS constraints of devices into + * account, because constraints updated after the device has + * been suspended are not guaranteed to be taken into account + * anyway. In order for them to take effect, the device has to + * be resumed and suspended again. + */ constraint_ns = dev_gpd_data(dev)->td.effective_constraint_ns; - - if (constraint_ns < 0) { + } else { + /* + * The child is not in a domain and there's no info on its + * suspend/resume latencies, so assume them to be negligible and + * take its current PM QoS constraint (that's the only thing + * known at this point anyway). + */ constraint_ns = dev_pm_qos_read_value(dev); constraint_ns *= NSEC_PER_USEC; } - if (constraint_ns == 0) - return 0; - /* - * constraint_ns cannot be negative here, because the device has been - * suspended. - */ - if (constraint_ns < *constraint_ns_p || *constraint_ns_p == 0) + if (constraint_ns < *constraint_ns_p) *constraint_ns_p = constraint_ns; return 0; @@ -58,12 +64,12 @@ static bool default_suspend_ok(struct device *dev) } td->constraint_changed = false; td->cached_suspend_ok = false; - td->effective_constraint_ns = -1; + td->effective_constraint_ns = 0; constraint_ns = __dev_pm_qos_read_value(dev); spin_unlock_irqrestore(&dev->power.lock, flags); - if (constraint_ns < 0) + if (constraint_ns == 0) return false; constraint_ns *= NSEC_PER_USEC; @@ -76,14 +82,32 @@ static bool default_suspend_ok(struct device *dev) device_for_each_child(dev, &constraint_ns, dev_update_qos_constraint); - if (constraint_ns > 0) { + if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS) { + /* "No restriction", so the device is allowed to suspend. */ + td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS; + td->cached_suspend_ok = true; + } else if (constraint_ns == 0) { + /* + * This triggers if one of the children that don't belong to a + * domain has a zero PM QoS constraint and it's better not to + * suspend then. effective_constraint_ns is zero already and + * cached_suspend_ok is false, so bail out. + */ + return false; + } else { constraint_ns -= td->suspend_latency_ns + td->resume_latency_ns; - if (constraint_ns == 0) + /* + * effective_constraint_ns is zero already and cached_suspend_ok + * is false, so if the computed value is not positive, return + * right away. + */ + if (constraint_ns <= 0) return false; + + td->effective_constraint_ns = constraint_ns; + td->cached_suspend_ok = true; } - td->effective_constraint_ns = constraint_ns; - td->cached_suspend_ok = constraint_ns >= 0; /* * The children have been suspended already, so we don't need to take @@ -144,18 +168,13 @@ static bool __default_power_down_ok(struct dev_pm_domain *pd, */ td = &to_gpd_data(pdd)->td; constraint_ns = td->effective_constraint_ns; - /* default_suspend_ok() need not be called before us. */ - if (constraint_ns < 0) { - constraint_ns = dev_pm_qos_read_value(pdd->dev); - constraint_ns *= NSEC_PER_USEC; - } - if (constraint_ns == 0) - continue; - /* - * constraint_ns cannot be negative here, because the device has - * been suspended. + * Zero means "no suspend at all" and this runs only when all + * devices in the domain are suspended, so it must be positive. */ + if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS) + continue; + if (constraint_ns <= off_on_time_ns) return false; |