OpenCloudOS-Kernel/drivers/base/power/sysfs.c

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/*
* drivers/base/power/sysfs.c - sysfs entries for device PM
*/
#include <linux/device.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/pm_qos.h>
#include <linux/pm_runtime.h>
#include <linux/atomic.h>
#include <linux/jiffies.h>
#include "power.h"
/*
* control - Report/change current runtime PM setting of the device
*
* Runtime power management of a device can be blocked with the help of
* this attribute. All devices have one of the following two values for
* the power/control file:
*
* + "auto\n" to allow the device to be power managed at run time;
* + "on\n" to prevent the device from being power managed at run time;
*
* The default for all devices is "auto", which means that devices may be
* subject to automatic power management, depending on their drivers.
* Changing this attribute to "on" prevents the driver from power managing
* the device at run time. Doing that while the device is suspended causes
* it to be woken up.
*
* wakeup - Report/change current wakeup option for device
*
* Some devices support "wakeup" events, which are hardware signals
* used to activate devices from suspended or low power states. Such
* devices have one of three values for the sysfs power/wakeup file:
*
* + "enabled\n" to issue the events;
* + "disabled\n" not to do so; or
* + "\n" for temporary or permanent inability to issue wakeup.
*
* (For example, unconfigured USB devices can't issue wakeups.)
*
* Familiar examples of devices that can issue wakeup events include
* keyboards and mice (both PS2 and USB styles), power buttons, modems,
* "Wake-On-LAN" Ethernet links, GPIO lines, and more. Some events
* will wake the entire system from a suspend state; others may just
* wake up the device (if the system as a whole is already active).
* Some wakeup events use normal IRQ lines; other use special out
* of band signaling.
*
* It is the responsibility of device drivers to enable (or disable)
* wakeup signaling as part of changing device power states, respecting
* the policy choices provided through the driver model.
*
* Devices may not be able to generate wakeup events from all power
* states. Also, the events may be ignored in some configurations;
* for example, they might need help from other devices that aren't
* active, or which may have wakeup disabled. Some drivers rely on
* wakeup events internally (unless they are disabled), keeping
* their hardware in low power modes whenever they're unused. This
* saves runtime power, without requiring system-wide sleep states.
*
* async - Report/change current async suspend setting for the device
*
* Asynchronous suspend and resume of the device during system-wide power
* state transitions can be enabled by writing "enabled" to this file.
* Analogously, if "disabled" is written to this file, the device will be
* suspended and resumed synchronously.
*
* All devices have one of the following two values for power/async:
*
* + "enabled\n" to permit the asynchronous suspend/resume of the device;
* + "disabled\n" to forbid it;
*
* NOTE: It generally is unsafe to permit the asynchronous suspend/resume
* of a device unless it is certain that all of the PM dependencies of the
* device are known to the PM core. However, for some devices this
* attribute is set to "enabled" by bus type code or device drivers and in
* that cases it should be safe to leave the default value.
PM: Make it possible to avoid races between wakeup and system sleep One of the arguments during the suspend blockers discussion was that the mainline kernel didn't contain any mechanisms making it possible to avoid races between wakeup and system suspend. Generally, there are two problems in that area. First, if a wakeup event occurs exactly when /sys/power/state is being written to, it may be delivered to user space right before the freezer kicks in, so the user space consumer of the event may not be able to process it before the system is suspended. Second, if a wakeup event occurs after user space has been frozen, it is not generally guaranteed that the ongoing transition of the system into a sleep state will be aborted. To address these issues introduce a new global sysfs attribute, /sys/power/wakeup_count, associated with a running counter of wakeup events and three helper functions, pm_stay_awake(), pm_relax(), and pm_wakeup_event(), that may be used by kernel subsystems to control the behavior of this attribute and to request the PM core to abort system transitions into a sleep state already in progress. The /sys/power/wakeup_count file may be read from or written to by user space. Reads will always succeed (unless interrupted by a signal) and return the current value of the wakeup events counter. Writes, however, will only succeed if the written number is equal to the current value of the wakeup events counter. If a write is successful, it will cause the kernel to save the current value of the wakeup events counter and to abort the subsequent system transition into a sleep state if any wakeup events are reported after the write has returned. [The assumption is that before writing to /sys/power/state user space will first read from /sys/power/wakeup_count. Next, user space consumers of wakeup events will have a chance to acknowledge or veto the upcoming system transition to a sleep state. Finally, if the transition is allowed to proceed, /sys/power/wakeup_count will be written to and if that succeeds, /sys/power/state will be written to as well. Still, if any wakeup events are reported to the PM core by kernel subsystems after that point, the transition will be aborted.] Additionally, put a wakeup events counter into struct dev_pm_info and make these per-device wakeup event counters available via sysfs, so that it's possible to check the activity of various wakeup event sources within the kernel. To illustrate how subsystems can use pm_wakeup_event(), make the low-level PCI runtime PM wakeup-handling code use it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-07-06 04:43:53 +08:00
*
* autosuspend_delay_ms - Report/change a device's autosuspend_delay value
*
* Some drivers don't want to carry out a runtime suspend as soon as a
* device becomes idle; they want it always to remain idle for some period
* of time before suspending it. This period is the autosuspend_delay
* value (expressed in milliseconds) and it can be controlled by the user.
* If the value is negative then the device will never be runtime
* suspended.
*
* NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
* value are used only if the driver calls pm_runtime_use_autosuspend().
*
PM: Make it possible to avoid races between wakeup and system sleep One of the arguments during the suspend blockers discussion was that the mainline kernel didn't contain any mechanisms making it possible to avoid races between wakeup and system suspend. Generally, there are two problems in that area. First, if a wakeup event occurs exactly when /sys/power/state is being written to, it may be delivered to user space right before the freezer kicks in, so the user space consumer of the event may not be able to process it before the system is suspended. Second, if a wakeup event occurs after user space has been frozen, it is not generally guaranteed that the ongoing transition of the system into a sleep state will be aborted. To address these issues introduce a new global sysfs attribute, /sys/power/wakeup_count, associated with a running counter of wakeup events and three helper functions, pm_stay_awake(), pm_relax(), and pm_wakeup_event(), that may be used by kernel subsystems to control the behavior of this attribute and to request the PM core to abort system transitions into a sleep state already in progress. The /sys/power/wakeup_count file may be read from or written to by user space. Reads will always succeed (unless interrupted by a signal) and return the current value of the wakeup events counter. Writes, however, will only succeed if the written number is equal to the current value of the wakeup events counter. If a write is successful, it will cause the kernel to save the current value of the wakeup events counter and to abort the subsequent system transition into a sleep state if any wakeup events are reported after the write has returned. [The assumption is that before writing to /sys/power/state user space will first read from /sys/power/wakeup_count. Next, user space consumers of wakeup events will have a chance to acknowledge or veto the upcoming system transition to a sleep state. Finally, if the transition is allowed to proceed, /sys/power/wakeup_count will be written to and if that succeeds, /sys/power/state will be written to as well. Still, if any wakeup events are reported to the PM core by kernel subsystems after that point, the transition will be aborted.] Additionally, put a wakeup events counter into struct dev_pm_info and make these per-device wakeup event counters available via sysfs, so that it's possible to check the activity of various wakeup event sources within the kernel. To illustrate how subsystems can use pm_wakeup_event(), make the low-level PCI runtime PM wakeup-handling code use it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-07-06 04:43:53 +08:00
* wakeup_count - Report the number of wakeup events related to the device
*/
const char power_group_name[] = "power";
EXPORT_SYMBOL_GPL(power_group_name);
static const char ctrl_auto[] = "auto";
static const char ctrl_on[] = "on";
static ssize_t control_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%s\n",
dev->power.runtime_auto ? ctrl_auto : ctrl_on);
}
static ssize_t control_store(struct device * dev, struct device_attribute *attr,
const char * buf, size_t n)
{
device_lock(dev);
if (sysfs_streq(buf, ctrl_auto))
pm_runtime_allow(dev);
else if (sysfs_streq(buf, ctrl_on))
pm_runtime_forbid(dev);
else
n = -EINVAL;
device_unlock(dev);
return n;
}
static DEVICE_ATTR(control, 0644, control_show, control_store);
static ssize_t rtpm_active_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int ret;
spin_lock_irq(&dev->power.lock);
update_pm_runtime_accounting(dev);
ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies));
spin_unlock_irq(&dev->power.lock);
return ret;
}
static DEVICE_ATTR(runtime_active_time, 0444, rtpm_active_time_show, NULL);
static ssize_t rtpm_suspended_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int ret;
spin_lock_irq(&dev->power.lock);
update_pm_runtime_accounting(dev);
ret = sprintf(buf, "%i\n",
jiffies_to_msecs(dev->power.suspended_jiffies));
spin_unlock_irq(&dev->power.lock);
return ret;
}
static DEVICE_ATTR(runtime_suspended_time, 0444, rtpm_suspended_time_show, NULL);
static ssize_t rtpm_status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
const char *p;
if (dev->power.runtime_error) {
p = "error\n";
} else if (dev->power.disable_depth) {
p = "unsupported\n";
} else {
switch (dev->power.runtime_status) {
case RPM_SUSPENDED:
p = "suspended\n";
break;
case RPM_SUSPENDING:
p = "suspending\n";
break;
case RPM_RESUMING:
p = "resuming\n";
break;
case RPM_ACTIVE:
p = "active\n";
break;
default:
return -EIO;
}
}
return sprintf(buf, p);
}
static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);
static ssize_t autosuspend_delay_ms_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
if (!dev->power.use_autosuspend)
return -EIO;
return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
}
static ssize_t autosuspend_delay_ms_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t n)
{
long delay;
if (!dev->power.use_autosuspend)
return -EIO;
if (kstrtol(buf, 10, &delay) != 0 || delay != (int) delay)
return -EINVAL;
device_lock(dev);
pm_runtime_set_autosuspend_delay(dev, delay);
device_unlock(dev);
return n;
}
static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
autosuspend_delay_ms_store);
static ssize_t pm_qos_resume_latency_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
PM / QoS: Fix device resume latency framework 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>
2017-11-07 18:33:49 +08:00
s32 value = dev_pm_qos_requested_resume_latency(dev);
if (value == 0)
return sprintf(buf, "n/a\n");
else if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
value = 0;
return sprintf(buf, "%d\n", value);
}
static ssize_t pm_qos_resume_latency_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t n)
{
s32 value;
int ret;
PM / QoS: Fix device resume latency framework 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>
2017-11-07 18:33:49 +08:00
if (!kstrtos32(buf, 0, &value)) {
/*
* Prevent users from writing negative or "no constraint" values
* directly.
*/
if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
return -EINVAL;
if (value == 0)
value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
} else if (sysfs_streq(buf, "n/a")) {
PM / QoS: Fix device resume latency framework 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>
2017-11-07 18:33:49 +08:00
value = 0;
} else {
return -EINVAL;
PM / QoS: Fix device resume latency framework 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>
2017-11-07 18:33:49 +08:00
}
ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
value);
return ret < 0 ? ret : n;
}
static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
pm_qos_resume_latency_show, pm_qos_resume_latency_store);
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
static ssize_t pm_qos_latency_tolerance_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
if (value < 0)
return sprintf(buf, "auto\n");
else if (value == PM_QOS_LATENCY_ANY)
return sprintf(buf, "any\n");
return sprintf(buf, "%d\n", value);
}
static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t n)
{
s32 value;
int ret;
if (kstrtos32(buf, 0, &value) == 0) {
/* Users can't write negative values directly */
if (value < 0)
return -EINVAL;
} else {
if (sysfs_streq(buf, "auto"))
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
else if (sysfs_streq(buf, "any"))
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
value = PM_QOS_LATENCY_ANY;
else
return -EINVAL;
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
}
ret = dev_pm_qos_update_user_latency_tolerance(dev, value);
return ret < 0 ? ret : n;
}
static DEVICE_ATTR(pm_qos_latency_tolerance_us, 0644,
pm_qos_latency_tolerance_show, pm_qos_latency_tolerance_store);
static ssize_t pm_qos_no_power_off_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
& PM_QOS_FLAG_NO_POWER_OFF));
}
static ssize_t pm_qos_no_power_off_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t n)
{
int ret;
if (kstrtoint(buf, 0, &ret))
return -EINVAL;
if (ret != 0 && ret != 1)
return -EINVAL;
ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
return ret < 0 ? ret : n;
}
static DEVICE_ATTR(pm_qos_no_power_off, 0644,
pm_qos_no_power_off_show, pm_qos_no_power_off_store);
#ifdef CONFIG_PM_SLEEP
static const char _enabled[] = "enabled";
static const char _disabled[] = "disabled";
static ssize_t
wake_show(struct device * dev, struct device_attribute *attr, char * buf)
{
return sprintf(buf, "%s\n", device_can_wakeup(dev)
? (device_may_wakeup(dev) ? _enabled : _disabled)
: "");
}
static ssize_t
wake_store(struct device * dev, struct device_attribute *attr,
const char * buf, size_t n)
{
if (!device_can_wakeup(dev))
return -EINVAL;
if (sysfs_streq(buf, _enabled))
device_set_wakeup_enable(dev, 1);
else if (sysfs_streq(buf, _disabled))
device_set_wakeup_enable(dev, 0);
else
return -EINVAL;
return n;
}
static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
PM: Make it possible to avoid races between wakeup and system sleep One of the arguments during the suspend blockers discussion was that the mainline kernel didn't contain any mechanisms making it possible to avoid races between wakeup and system suspend. Generally, there are two problems in that area. First, if a wakeup event occurs exactly when /sys/power/state is being written to, it may be delivered to user space right before the freezer kicks in, so the user space consumer of the event may not be able to process it before the system is suspended. Second, if a wakeup event occurs after user space has been frozen, it is not generally guaranteed that the ongoing transition of the system into a sleep state will be aborted. To address these issues introduce a new global sysfs attribute, /sys/power/wakeup_count, associated with a running counter of wakeup events and three helper functions, pm_stay_awake(), pm_relax(), and pm_wakeup_event(), that may be used by kernel subsystems to control the behavior of this attribute and to request the PM core to abort system transitions into a sleep state already in progress. The /sys/power/wakeup_count file may be read from or written to by user space. Reads will always succeed (unless interrupted by a signal) and return the current value of the wakeup events counter. Writes, however, will only succeed if the written number is equal to the current value of the wakeup events counter. If a write is successful, it will cause the kernel to save the current value of the wakeup events counter and to abort the subsequent system transition into a sleep state if any wakeup events are reported after the write has returned. [The assumption is that before writing to /sys/power/state user space will first read from /sys/power/wakeup_count. Next, user space consumers of wakeup events will have a chance to acknowledge or veto the upcoming system transition to a sleep state. Finally, if the transition is allowed to proceed, /sys/power/wakeup_count will be written to and if that succeeds, /sys/power/state will be written to as well. Still, if any wakeup events are reported to the PM core by kernel subsystems after that point, the transition will be aborted.] Additionally, put a wakeup events counter into struct dev_pm_info and make these per-device wakeup event counters available via sysfs, so that it's possible to check the activity of various wakeup event sources within the kernel. To illustrate how subsystems can use pm_wakeup_event(), make the low-level PCI runtime PM wakeup-handling code use it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-07-06 04:43:53 +08:00
static ssize_t wakeup_count_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned long count = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
count = dev->power.wakeup->event_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
PM: Make it possible to avoid races between wakeup and system sleep One of the arguments during the suspend blockers discussion was that the mainline kernel didn't contain any mechanisms making it possible to avoid races between wakeup and system suspend. Generally, there are two problems in that area. First, if a wakeup event occurs exactly when /sys/power/state is being written to, it may be delivered to user space right before the freezer kicks in, so the user space consumer of the event may not be able to process it before the system is suspended. Second, if a wakeup event occurs after user space has been frozen, it is not generally guaranteed that the ongoing transition of the system into a sleep state will be aborted. To address these issues introduce a new global sysfs attribute, /sys/power/wakeup_count, associated with a running counter of wakeup events and three helper functions, pm_stay_awake(), pm_relax(), and pm_wakeup_event(), that may be used by kernel subsystems to control the behavior of this attribute and to request the PM core to abort system transitions into a sleep state already in progress. The /sys/power/wakeup_count file may be read from or written to by user space. Reads will always succeed (unless interrupted by a signal) and return the current value of the wakeup events counter. Writes, however, will only succeed if the written number is equal to the current value of the wakeup events counter. If a write is successful, it will cause the kernel to save the current value of the wakeup events counter and to abort the subsequent system transition into a sleep state if any wakeup events are reported after the write has returned. [The assumption is that before writing to /sys/power/state user space will first read from /sys/power/wakeup_count. Next, user space consumers of wakeup events will have a chance to acknowledge or veto the upcoming system transition to a sleep state. Finally, if the transition is allowed to proceed, /sys/power/wakeup_count will be written to and if that succeeds, /sys/power/state will be written to as well. Still, if any wakeup events are reported to the PM core by kernel subsystems after that point, the transition will be aborted.] Additionally, put a wakeup events counter into struct dev_pm_info and make these per-device wakeup event counters available via sysfs, so that it's possible to check the activity of various wakeup event sources within the kernel. To illustrate how subsystems can use pm_wakeup_event(), make the low-level PCI runtime PM wakeup-handling code use it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-07-06 04:43:53 +08:00
}
static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
static ssize_t wakeup_active_count_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned long count = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
count = dev->power.wakeup->active_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);
static ssize_t wakeup_abort_count_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
unsigned long count = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
count = dev->power.wakeup->wakeup_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_abort_count, 0444, wakeup_abort_count_show, NULL);
static ssize_t wakeup_expire_count_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
unsigned long count = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
count = dev->power.wakeup->expire_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_expire_count, 0444, wakeup_expire_count_show, NULL);
static ssize_t wakeup_active_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned int active = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
active = dev->power.wakeup->active;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);
static ssize_t wakeup_total_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
s64 msec = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
msec = ktime_to_ms(dev->power.wakeup->total_time);
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);
static ssize_t wakeup_max_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
s64 msec = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
msec = ktime_to_ms(dev->power.wakeup->max_time);
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);
static ssize_t wakeup_last_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
s64 msec = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
msec = ktime_to_ms(dev->power.wakeup->last_time);
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
#ifdef CONFIG_PM_AUTOSLEEP
static ssize_t wakeup_prevent_sleep_time_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
s64 msec = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_prevent_sleep_time_ms, 0444,
wakeup_prevent_sleep_time_show, NULL);
#endif /* CONFIG_PM_AUTOSLEEP */
#endif /* CONFIG_PM_SLEEP */
PM: Make it possible to avoid races between wakeup and system sleep One of the arguments during the suspend blockers discussion was that the mainline kernel didn't contain any mechanisms making it possible to avoid races between wakeup and system suspend. Generally, there are two problems in that area. First, if a wakeup event occurs exactly when /sys/power/state is being written to, it may be delivered to user space right before the freezer kicks in, so the user space consumer of the event may not be able to process it before the system is suspended. Second, if a wakeup event occurs after user space has been frozen, it is not generally guaranteed that the ongoing transition of the system into a sleep state will be aborted. To address these issues introduce a new global sysfs attribute, /sys/power/wakeup_count, associated with a running counter of wakeup events and three helper functions, pm_stay_awake(), pm_relax(), and pm_wakeup_event(), that may be used by kernel subsystems to control the behavior of this attribute and to request the PM core to abort system transitions into a sleep state already in progress. The /sys/power/wakeup_count file may be read from or written to by user space. Reads will always succeed (unless interrupted by a signal) and return the current value of the wakeup events counter. Writes, however, will only succeed if the written number is equal to the current value of the wakeup events counter. If a write is successful, it will cause the kernel to save the current value of the wakeup events counter and to abort the subsequent system transition into a sleep state if any wakeup events are reported after the write has returned. [The assumption is that before writing to /sys/power/state user space will first read from /sys/power/wakeup_count. Next, user space consumers of wakeup events will have a chance to acknowledge or veto the upcoming system transition to a sleep state. Finally, if the transition is allowed to proceed, /sys/power/wakeup_count will be written to and if that succeeds, /sys/power/state will be written to as well. Still, if any wakeup events are reported to the PM core by kernel subsystems after that point, the transition will be aborted.] Additionally, put a wakeup events counter into struct dev_pm_info and make these per-device wakeup event counters available via sysfs, so that it's possible to check the activity of various wakeup event sources within the kernel. To illustrate how subsystems can use pm_wakeup_event(), make the low-level PCI runtime PM wakeup-handling code use it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-07-06 04:43:53 +08:00
#ifdef CONFIG_PM_ADVANCED_DEBUG
static ssize_t rtpm_usagecount_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
}
static ssize_t rtpm_children_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", dev->power.ignore_children ?
0 : atomic_read(&dev->power.child_count));
}
static ssize_t rtpm_enabled_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
if ((dev->power.disable_depth) && (dev->power.runtime_auto == false))
return sprintf(buf, "disabled & forbidden\n");
else if (dev->power.disable_depth)
return sprintf(buf, "disabled\n");
else if (dev->power.runtime_auto == false)
return sprintf(buf, "forbidden\n");
return sprintf(buf, "enabled\n");
}
static DEVICE_ATTR(runtime_usage, 0444, rtpm_usagecount_show, NULL);
static DEVICE_ATTR(runtime_active_kids, 0444, rtpm_children_show, NULL);
static DEVICE_ATTR(runtime_enabled, 0444, rtpm_enabled_show, NULL);
#ifdef CONFIG_PM_SLEEP
static ssize_t async_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%s\n",
device_async_suspend_enabled(dev) ?
_enabled : _disabled);
}
static ssize_t async_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t n)
{
if (sysfs_streq(buf, _enabled))
device_enable_async_suspend(dev);
else if (sysfs_streq(buf, _disabled))
device_disable_async_suspend(dev);
else
return -EINVAL;
return n;
}
static DEVICE_ATTR(async, 0644, async_show, async_store);
#endif /* CONFIG_PM_SLEEP */
#endif /* CONFIG_PM_ADVANCED_DEBUG */
static struct attribute *power_attrs[] = {
#ifdef CONFIG_PM_ADVANCED_DEBUG
#ifdef CONFIG_PM_SLEEP
&dev_attr_async.attr,
#endif
&dev_attr_runtime_status.attr,
&dev_attr_runtime_usage.attr,
&dev_attr_runtime_active_kids.attr,
&dev_attr_runtime_enabled.attr,
#endif /* CONFIG_PM_ADVANCED_DEBUG */
NULL,
};
static const struct attribute_group pm_attr_group = {
.name = power_group_name,
.attrs = power_attrs,
};
static struct attribute *wakeup_attrs[] = {
#ifdef CONFIG_PM_SLEEP
&dev_attr_wakeup.attr,
&dev_attr_wakeup_count.attr,
&dev_attr_wakeup_active_count.attr,
&dev_attr_wakeup_abort_count.attr,
&dev_attr_wakeup_expire_count.attr,
&dev_attr_wakeup_active.attr,
&dev_attr_wakeup_total_time_ms.attr,
&dev_attr_wakeup_max_time_ms.attr,
&dev_attr_wakeup_last_time_ms.attr,
#ifdef CONFIG_PM_AUTOSLEEP
&dev_attr_wakeup_prevent_sleep_time_ms.attr,
#endif
#endif
NULL,
};
static const struct attribute_group pm_wakeup_attr_group = {
.name = power_group_name,
.attrs = wakeup_attrs,
};
static struct attribute *runtime_attrs[] = {
#ifndef CONFIG_PM_ADVANCED_DEBUG
&dev_attr_runtime_status.attr,
#endif
&dev_attr_control.attr,
&dev_attr_runtime_suspended_time.attr,
&dev_attr_runtime_active_time.attr,
&dev_attr_autosuspend_delay_ms.attr,
NULL,
};
static const struct attribute_group pm_runtime_attr_group = {
.name = power_group_name,
.attrs = runtime_attrs,
};
static struct attribute *pm_qos_resume_latency_attrs[] = {
&dev_attr_pm_qos_resume_latency_us.attr,
NULL,
};
static const struct attribute_group pm_qos_resume_latency_attr_group = {
.name = power_group_name,
.attrs = pm_qos_resume_latency_attrs,
};
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
static struct attribute *pm_qos_latency_tolerance_attrs[] = {
&dev_attr_pm_qos_latency_tolerance_us.attr,
NULL,
};
static const struct attribute_group pm_qos_latency_tolerance_attr_group = {
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
.name = power_group_name,
.attrs = pm_qos_latency_tolerance_attrs,
};
static struct attribute *pm_qos_flags_attrs[] = {
&dev_attr_pm_qos_no_power_off.attr,
NULL,
};
static const struct attribute_group pm_qos_flags_attr_group = {
.name = power_group_name,
.attrs = pm_qos_flags_attrs,
};
int dpm_sysfs_add(struct device *dev)
{
int rc;
rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
if (rc)
return rc;
if (pm_runtime_callbacks_present(dev)) {
rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
if (rc)
goto err_out;
}
if (device_can_wakeup(dev)) {
rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
if (rc)
goto err_runtime;
}
if (dev->power.set_latency_tolerance) {
rc = sysfs_merge_group(&dev->kobj,
&pm_qos_latency_tolerance_attr_group);
if (rc)
goto err_wakeup;
}
return 0;
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
err_wakeup:
sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
err_runtime:
sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
err_out:
sysfs_remove_group(&dev->kobj, &pm_attr_group);
return rc;
}
int wakeup_sysfs_add(struct device *dev)
{
return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
}
void wakeup_sysfs_remove(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
}
int pm_qos_sysfs_add_resume_latency(struct device *dev)
{
return sysfs_merge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
}
void pm_qos_sysfs_remove_resume_latency(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
}
int pm_qos_sysfs_add_flags(struct device *dev)
{
return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
}
void pm_qos_sysfs_remove_flags(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
}
int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
{
return sysfs_merge_group(&dev->kobj,
&pm_qos_latency_tolerance_attr_group);
}
void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
}
void rpm_sysfs_remove(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
}
void dpm_sysfs_remove(struct device *dev)
{
PM / QoS: Introcuce latency tolerance device PM QoS type Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-11 07:35:38 +08:00
sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
dev_pm_qos_constraints_destroy(dev);
rpm_sysfs_remove(dev);
sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
sysfs_remove_group(&dev->kobj, &pm_attr_group);
}