Skip to content

Commit

Permalink
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…
Browse files Browse the repository at this point in the history
…/git/rafael/suspend-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM: PM QOS update fix
  Freezer / cgroup freezer: Update stale locking comments
  PM / platform_bus: Allow runtime PM by default
  i2c: Fix bus-level power management callbacks
  PM QOS update
  PM / Hibernate: Fix block_io.c printk warning
  PM / Hibernate: Group swap ops
  PM / Hibernate: Move the first_sector out of swsusp_write
  PM / Hibernate: Separate block_io
  PM / Hibernate: Snapshot cleanup
  FS / libfs: Implement simple_write_to_buffer
  PM / Hibernate: document open(/dev/snapshot) side effects
  PM / Runtime: Add sysfs debug files
  PM: Improve device power management document
  PM: Update device power management document
  PM: Allow runtime_suspend methods to call pm_schedule_suspend()
  PM: pm_wakeup - switch to using bool
  • Loading branch information
torvalds committed May 20, 2010
2 parents fa5312d + 25f3a5a commit 46ee964
Show file tree
Hide file tree
Showing 31 changed files with 1,251 additions and 949 deletions.
847 changes: 483 additions & 364 deletions Documentation/power/devices.txt

Large diffs are not rendered by default.

48 changes: 25 additions & 23 deletions Documentation/power/pm_qos_interface.txt
Original file line number Diff line number Diff line change
Expand Up @@ -18,44 +18,46 @@ and pm_qos_params.h. This is done because having the available parameters
being runtime configurable or changeable from a driver was seen as too easy to
abuse.

For each parameter a list of performance requirements is maintained along with
For each parameter a list of performance requests is maintained along with
an aggregated target value. The aggregated target value is updated with
changes to the requirement list or elements of the list. Typically the
aggregated target value is simply the max or min of the requirement values held
changes to the request list or elements of the list. Typically the
aggregated target value is simply the max or min of the request values held
in the parameter list elements.

From kernel mode the use of this interface is simple:
pm_qos_add_requirement(param_id, name, target_value):
Will insert a named element in the list for that identified PM_QOS parameter
with the target value. Upon change to this list the new target is recomputed
and any registered notifiers are called only if the target value is now
different.

pm_qos_update_requirement(param_id, name, new_target_value):
Will search the list identified by the param_id for the named list element and
then update its target value, calling the notification tree if the aggregated
target is changed. with that name is already registered.
handle = pm_qos_add_request(param_class, target_value):
Will insert an element into the list for that identified PM_QOS class with the
target value. Upon change to this list the new target is recomputed and any
registered notifiers are called only if the target value is now different.
Clients of pm_qos need to save the returned handle.

pm_qos_remove_requirement(param_id, name):
Will search the identified list for the named element and remove it, after
removal it will update the aggregate target and call the notification tree if
the target was changed as a result of removing the named requirement.
void pm_qos_update_request(handle, new_target_value):
Will update the list element pointed to by the handle with the new target value
and recompute the new aggregated target, calling the notification tree if the
target is changed.

void pm_qos_remove_request(handle):
Will remove the element. After removal it will update the aggregate target and
call the notification tree if the target was changed as a result of removing
the request.


From user mode:
Only processes can register a pm_qos requirement. To provide for automatic
cleanup for process the interface requires the process to register its
parameter requirements in the following way:
Only processes can register a pm_qos request. To provide for automatic
cleanup of a process, the interface requires the process to register its
parameter requests in the following way:

To register the default pm_qos target for the specific parameter, the process
must open one of /dev/[cpu_dma_latency, network_latency, network_throughput]

As long as the device node is held open that process has a registered
requirement on the parameter. The name of the requirement is "process_<PID>"
derived from the current->pid from within the open system call.
request on the parameter.

To change the requested target value the process needs to write a s32 value to
the open device node. This translates to a pm_qos_update_requirement call.
To change the requested target value the process needs to write an s32 value to
the open device node. Alternatively the user mode program could write a hex
string for the value using 10 char long format e.g. "0x12345678". This
translates to a pm_qos_update_request call.

To remove the user mode request for a target value simply close the device
node.
Expand Down
4 changes: 4 additions & 0 deletions Documentation/power/userland-swsusp.txt
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,10 @@ assumed to be in the resume mode. The device cannot be open for simultaneous
reading and writing. It is also impossible to have the device open more than
once at a time.

Even opening the device has side effects. Data structures are
allocated, and PM_HIBERNATION_PREPARE / PM_RESTORE_PREPARE chains are
called.

The ioctl() commands recognized by the device are:

SNAPSHOT_FREEZE - freeze user space processes (the current process is
Expand Down
2 changes: 1 addition & 1 deletion drivers/acpi/processor_idle.c
Original file line number Diff line number Diff line change
Expand Up @@ -698,7 +698,7 @@ static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
"max_cstate: C%d\n"
"maximum allowed latency: %d usec\n",
pr->power.state ? pr->power.state - pr->power.states : 0,
max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
max_cstate, pm_qos_request(PM_QOS_CPU_DMA_LATENCY));

seq_puts(seq, "states:\n");

Expand Down
6 changes: 3 additions & 3 deletions drivers/base/platform.c
Original file line number Diff line number Diff line change
Expand Up @@ -967,17 +967,17 @@ static int platform_pm_restore_noirq(struct device *dev)

int __weak platform_pm_runtime_suspend(struct device *dev)
{
return -ENOSYS;
return pm_generic_runtime_suspend(dev);
};

int __weak platform_pm_runtime_resume(struct device *dev)
{
return -ENOSYS;
return pm_generic_runtime_resume(dev);
};

int __weak platform_pm_runtime_idle(struct device *dev)
{
return -ENOSYS;
return pm_generic_runtime_idle(dev);
};

#else /* !CONFIG_PM_RUNTIME */
Expand Down
10 changes: 5 additions & 5 deletions drivers/base/power/runtime.c
Original file line number Diff line number Diff line change
Expand Up @@ -229,14 +229,16 @@ int __pm_runtime_suspend(struct device *dev, bool from_wq)

if (retval) {
dev->power.runtime_status = RPM_ACTIVE;
pm_runtime_cancel_pending(dev);

if (retval == -EAGAIN || retval == -EBUSY) {
notify = true;
if (dev->power.timer_expires == 0)
notify = true;
dev->power.runtime_error = 0;
} else {
pm_runtime_cancel_pending(dev);
}
} else {
dev->power.runtime_status = RPM_SUSPENDED;
pm_runtime_deactivate_timer(dev);

if (dev->parent) {
parent = dev->parent;
Expand Down Expand Up @@ -659,8 +661,6 @@ int pm_schedule_suspend(struct device *dev, unsigned int delay)

if (dev->power.runtime_status == RPM_SUSPENDED)
retval = 1;
else if (dev->power.runtime_status == RPM_SUSPENDING)
retval = -EINPROGRESS;
else if (atomic_read(&dev->power.usage_count) > 0
|| dev->power.disable_depth > 0)
retval = -EAGAIN;
Expand Down
65 changes: 62 additions & 3 deletions drivers/base/power/sysfs.c
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@
#include <linux/device.h>
#include <linux/string.h>
#include <linux/pm_runtime.h>
#include <asm/atomic.h>
#include "power.h"

/*
Expand Down Expand Up @@ -143,7 +144,59 @@ wake_store(struct device * dev, struct device_attribute *attr,

static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);

#ifdef CONFIG_PM_SLEEP_ADVANCED_DEBUG
#ifdef CONFIG_PM_ADVANCED_DEBUG
#ifdef CONFIG_PM_RUNTIME

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 ssize_t rtpm_status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
if (dev->power.runtime_error)
return sprintf(buf, "error\n");
switch (dev->power.runtime_status) {
case RPM_SUSPENDED:
return sprintf(buf, "suspended\n");
case RPM_SUSPENDING:
return sprintf(buf, "suspending\n");
case RPM_RESUMING:
return sprintf(buf, "resuming\n");
case RPM_ACTIVE:
return sprintf(buf, "active\n");
}
return -EIO;
}

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_status, 0444, rtpm_status_show, NULL);
static DEVICE_ATTR(runtime_enabled, 0444, rtpm_enabled_show, NULL);

#endif

static ssize_t async_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
Expand All @@ -170,15 +223,21 @@ static ssize_t async_store(struct device *dev, struct device_attribute *attr,
}

static DEVICE_ATTR(async, 0644, async_show, async_store);
#endif /* CONFIG_PM_SLEEP_ADVANCED_DEBUG */
#endif /* CONFIG_PM_ADVANCED_DEBUG */

static struct attribute * power_attrs[] = {
#ifdef CONFIG_PM_RUNTIME
&dev_attr_control.attr,
#endif
&dev_attr_wakeup.attr,
#ifdef CONFIG_PM_SLEEP_ADVANCED_DEBUG
#ifdef CONFIG_PM_ADVANCED_DEBUG
&dev_attr_async.attr,
#ifdef CONFIG_PM_RUNTIME
&dev_attr_runtime_usage.attr,
&dev_attr_runtime_active_kids.attr,
&dev_attr_runtime_status.attr,
&dev_attr_runtime_enabled.attr,
#endif
#endif
NULL,
};
Expand Down
2 changes: 1 addition & 1 deletion drivers/cpuidle/governors/ladder.c
Original file line number Diff line number Diff line change
Expand Up @@ -67,7 +67,7 @@ static int ladder_select_state(struct cpuidle_device *dev)
struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
struct ladder_device_state *last_state;
int last_residency, last_idx = ldev->last_state_idx;
int latency_req = pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY);
int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);

/* Special case when user has set very strict latency requirement */
if (unlikely(latency_req == 0)) {
Expand Down
2 changes: 1 addition & 1 deletion drivers/cpuidle/governors/menu.c
Original file line number Diff line number Diff line change
Expand Up @@ -182,7 +182,7 @@ static u64 div_round64(u64 dividend, u32 divisor)
static int menu_select(struct cpuidle_device *dev)
{
struct menu_device *data = &__get_cpu_var(menu_devices);
int latency_req = pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY);
int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
int i;
int multiplier;

Expand Down
Loading

0 comments on commit 46ee964

Please sign in to comment.