linux-stable.git/drivers/base/power/sysfs.c, branch linux-5.1.y Linux kernel stable tree PM-runtime: Call pm_runtime_active|suspended_time() from sysfs 2019-03-07T10:23:17+00:00 Ulf Hansson ulf.hansson@linaro.org 2019-03-05T12:55:35+00:00 0996584b3026bed7f38abe02e8535e6a6c474118 Avoid the open-coding of the accounted time acquisition in runtime_active|suspend_time_show() and make them call pm_runtime_active|suspended_time() instead. Note that this change also indirectly avoids holding dev->power.lock around the do_div() computation and the sprintf() call which is an additional improvement. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Avoid the open-coding of the accounted time acquisition in
runtime_active|suspend_time_show() and make them call
pm_runtime_active|suspended_time() instead.

Note that this change also indirectly avoids holding dev->power.lock
around the do_div() computation and the sprintf() call which is an
additional improvement.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / core: Add support to skip power management in device/driver model 2019-02-19T09:42:43+00:00 Sudeep Holla sudeep.holla@arm.com 2019-02-14T18:29:10+00:00 85945c28b5a888043cb2b54f880d80d8915f21f5 All device objects in the driver model contain fields that control the handling of various power management activities. However, it's not always useful. There are few instances where pseudo devices are added to the model just to take advantage of many other features like kobjects, udev events, and so on. One such example is cpu devices and their caches. The sysfs for the cpu caches are managed by adding devices with cpu as the parent in cpu_device_create() when secondary cpu is brought online. Generally when the secondary CPUs are hotplugged back in as part of resume from suspend-to-ram, we call cpu_device_create() from the cpu hotplug state machine while the cpu device associated with that CPU is not yet ready to be resumed as the device_resume() call happens bit later. It's not really needed to set the flag is_prepared for cpu devices as they are mostly pseudo device and hotplug framework deals with state machine and not managed through the cpu device. This often results in annoying warning when resuming: Enabling non-boot CPUs ... CPU1: Booted secondary processor cache: parent cpu1 should not be sleeping CPU1 is up CPU2: Booted secondary processor cache: parent cpu2 should not be sleeping CPU2 is up .... and so on. So in order to fix these kind of errors, we could just completely avoid doing any power management related initialisations and operations if they are not used by these devices. Add no_pm flags to indicate that the device doesn't require any sort of PM activities and all of them can be completely skipped. We can use the same flag to also avoid adding not used *power* sysfs entries for these devices. For now, lets use this for cpu cache devices. Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
All device objects in the driver model contain fields that control the
handling of various power management activities. However, it's not
always useful. There are few instances where pseudo devices are added
to the model just to take advantage of many other features like
kobjects, udev events, and so on. One such example is cpu devices and
their caches.

The sysfs for the cpu caches are managed by adding devices with cpu
as the parent in cpu_device_create() when secondary cpu is brought
online. Generally when the secondary CPUs are hotplugged back in as part
of resume from suspend-to-ram, we call cpu_device_create() from the cpu
hotplug state machine while the cpu device associated with that CPU is
not yet ready to be resumed as the device_resume() call happens bit
later. It's not really needed to set the flag is_prepared for cpu
devices as they are mostly pseudo device and hotplug framework deals
with state machine and not managed through the cpu device.

This often results in annoying warning when resuming:
Enabling non-boot CPUs ...
CPU1: Booted secondary processor
 cache: parent cpu1 should not be sleeping
CPU1 is up
CPU2: Booted secondary processor
 cache: parent cpu2 should not be sleeping
CPU2 is up
.... and so on.

So in order to fix these kind of errors, we could just completely avoid
doing any power management related initialisations and operations if
they are not used by these devices.

Add no_pm flags to indicate that the device doesn't require any sort of
PM activities and all of them can be completely skipped. We can use the
same flag to also avoid adding not used *power* sysfs entries for these
devices. For now, lets use this for cpu cache devices.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM-runtime: Replace jiffies-based accounting with ktime-based accounting 2019-01-31T09:45:10+00:00 Thara Gopinath thara.gopinath@linaro.org 2019-01-23T07:50:14+00:00 a08c2a5a31941131c41feaa0429e4c8854cf48f2 Replace jiffies-based accounting for runtime_active_time and runtime_suspended_time with ktime-based accounting. This makes the runtime debug counters inline with genpd and other PM subsytems which use ktime-based accounting. Timekeeping is initialized before driver_init(). It's only at that time that PM-runtime can be enabled. Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> [switch from ktime to raw nsec] 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> 
Replace jiffies-based accounting for runtime_active_time and
runtime_suspended_time with ktime-based accounting. This makes the
runtime debug counters inline with genpd and other PM subsytems which
use ktime-based accounting.

Timekeeping is initialized before driver_init(). It's only at that time
that PM-runtime can be enabled.

Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
[switch from ktime to raw nsec]
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 / wakeup: Export wakeup_count instead of event_count via sysfs 2018-06-06T07:23:36+00:00 Ravi Chandra Sadineni ravisadineni@chromium.org 2018-06-02T02:32:15+00:00 2d5ed61ce9820a1fe7b076cc45c169524d767746 Currently we export event_count instead of wakeup_count via the per-device wakeup_count sysfs attribute. Change it to wakeup_count to make it more meaningful. wakeup_count increments only when events_check_enabled is set, that is whenever writes the current wakeup count to /sys/power/wakeup_count. Also events_check_enabled is cleared on every resume. User space is expected to write to this just before suspend. This way pm_wakeup_event(), when called from IRQs handles, will increment wakeup_count only if we are in system-wide suspend-resume cycle and should give a fair approximation of how many times a device may have triggered a wakeup from system suspend. event_count on the other hand will increment every time pm_wakeup_event() is called irrespective of whether we are in a suspend-resume cycle and some drivers call it on every interrupt which makes it less useful for system wakeup tracking. Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org> Acked-by: Pavel Machek <pavel@ucw.cz> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Currently we export event_count instead of wakeup_count via the
per-device wakeup_count sysfs attribute. Change it to wakeup_count
to make it more meaningful.

wakeup_count increments only when events_check_enabled is set,
that is whenever writes the current wakeup count to
/sys/power/wakeup_count.  Also events_check_enabled is cleared on
every resume. User space is expected to write to this just before
suspend.  This way pm_wakeup_event(), when called from IRQs handles,
will increment wakeup_count only if we are in system-wide
suspend-resume cycle and should give a fair approximation of how many
times a device may have triggered a wakeup from system suspend.

event_count on the other hand will increment every time
pm_wakeup_event() is called irrespective of whether we are in a
suspend-resume cycle and some drivers call it on every interrupt
which makes it less useful for system wakeup tracking.

Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / sysfs: Convert to use DEVICE_ATTR_RO / DEVICE_ATTR_RW 2017-12-05T00:59:57+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2017-11-10T18:28:09+00:00 47acbd77e6e481abf2f41d3a99cb3762f296b2e6 Use DEVICE_ATTR_RO() and DEVICE_ATTR_RW() macros instead of open coding them. No functional change intended. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Use DEVICE_ATTR_RO() and DEVICE_ATTR_RW() macros instead of
open coding them.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / sysfs: Remove redundant 'else' keyword. 2017-12-05T00:59:57+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2017-11-10T18:28:08+00:00 f0e6d9f164c2269df69b6d2fe05c285392a6a0d4 There is no need to use 'else' if in main branch 'return' is present. No functional change intended. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
There is no need to use 'else' if in main branch 'return' is present.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / sysfs: Convert to use sysfs_streq() 2017-12-05T00:59:56+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2017-11-10T18:28:07+00:00 325c4b3b81027068914854adcba4e97200c809df ...instead of custom approach. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
...instead of custom approach.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / QoS: Fix device resume latency framework 2017-11-08T11:14:51+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2017-11-07T10:33:49+00:00 0759e80b84e34a84e7e46e2b1adb528c83d84a47 The special value of 0 for device resume latency PM QoS means "no restriction", but there are two problems with that. First, device resume latency PM QoS requests with 0 as the value are always put in front of requests with positive values in the priority lists used internally by the PM QoS framework, causing 0 to be chosen as an effective constraint value. However, that 0 is then interpreted as "no restriction" effectively overriding the other requests with specific restrictions which is incorrect. Second, the users of device resume latency PM QoS have no way to specify that *any* resume latency at all should be avoided, which is an artificial limitation in general. To address these issues, modify device resume latency PM QoS to use S32_MAX as the "no constraint" value and 0 as the "no latency at all" one and rework its users (the cpuidle menu governor, the genpd QoS governor and the runtime PM framework) to follow these changes. Also add a special "n/a" value to the corresponding user space I/F to allow user space to indicate that it cannot accept any resume latencies at all for the given device. Fixes: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints) Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323 Reported-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Tero Kristo <t-kristo@ti.com> Reviewed-by: Ramesh Thomas <ramesh.thomas@intel.com> 
The special value of 0 for device resume latency PM QoS means
"no restriction", but there are two problems with that.

First, device resume latency PM QoS requests with 0 as the
value are always put in front of requests with positive
values in the priority lists used internally by the PM QoS
framework, causing 0 to be chosen as an effective constraint
value.  However, that 0 is then interpreted as "no restriction"
effectively overriding the other requests with specific
restrictions which is incorrect.

Second, the users of device resume latency PM QoS have no
way to specify that *any* resume latency at all should be
avoided, which is an artificial limitation in general.

To address these issues, modify device resume latency PM QoS to
use S32_MAX as the "no constraint" value and 0 as the "no
latency at all" one and rework its users (the cpuidle menu
governor, the genpd QoS governor and the runtime PM framework)
to follow these changes.

Also add a special "n/a" value to the corresponding user space I/F
to allow user space to indicate that it cannot accept any resume
latencies at all for the given device.

Fixes: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Ramesh Thomas <ramesh.thomas@intel.com>
PM / QoS: Drop PM_QOS_FLAG_REMOTE_WAKEUP 2017-10-13T23:04:31+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2017-10-13T13:27:24+00:00 20f97caf1120bd02e8ff4adbad3b44b63626feb5 The PM QoS flag PM_QOS_FLAG_REMOTE_WAKEUP is not used consistently and the vast majority of code simply assumes that remote wakeup should be enabled for devices in runtime suspend if they can generate wakeup signals, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> 
The PM QoS flag PM_QOS_FLAG_REMOTE_WAKEUP is not used consistently
and the vast majority of code simply assumes that remote wakeup
should be enabled for devices in runtime suspend if they can
generate wakeup signals, so drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
PM / QoS: return -EINVAL for bogus strings 2017-07-12T12:42:37+00:00 Dan Carpenter dan.carpenter@oracle.com 2017-07-10T07:21:40+00:00 2ca30331c156ca9e97643ad05dd8930b8fe78b01 In the current code, if the user accidentally writes a bogus command to this sysfs file, then we set the latency tolerance to an uninitialized variable. Fixes: 2d984ad132a8 (PM / QoS: Introcuce latency tolerance device PM QoS type) Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: 3.15+ <stable@vger.kernel.org> # 3.15+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
In the current code, if the user accidentally writes a bogus command to
this sysfs file, then we set the latency tolerance to an uninitialized
variable.

Fixes: 2d984ad132a8 (PM / QoS: Introcuce latency tolerance device PM QoS type)
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>