Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: (26 commits)
  PM / Wakeup: Show wakeup sources statistics in debugfs
  PM: Introduce library for device-specific OPPs (v7)
  PM: Add sysfs attr for rechecking dev hash from PM trace
  PM: Lock PM device list mutex in show_dev_hash()
  PM / Runtime: Remove idle notification after failing suspend
  PM / Hibernate: Modify signature used to mark swap
  PM / Runtime: Reduce code duplication in core helper functions
  PM: Allow wakeup events to abort freezing of tasks
  PM: runtime: add missed pm_request_autosuspend
  PM / Hibernate: Make some boot messages look less scary
  PM / Runtime: Implement autosuspend support
  PM / Runtime: Add no_callbacks flag
  PM / Runtime: Combine runtime PM entry points
  PM / Runtime: Merge synchronous and async runtime routines
  PM / Runtime: Replace boolean arguments with bitflags
  PM / Runtime: Move code in drivers/base/power/runtime.c
  sysfs: Add sysfs_merge_group() and sysfs_unmerge_group()
  PM: Fix potential issue with failing asynchronous suspend
  PM / Wakeup: Introduce wakeup source objects and event statistics (v3)
  PM: Fix signed/unsigned warning in dpm_show_time()
  ...
This commit is contained in:
Linus Torvalds
2010-10-21 14:53:17 -07:00
33 changed files with 3491 additions and 679 deletions
@@ -77,3 +77,91 @@ Description:
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.
What: /sys/devices/.../power/wakeup_count
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_count attribute contains the number
of signaled wakeup events associated with the device. This
attribute is read-only. If the device is not enabled to wake up
the system from sleep states, this attribute is empty.
What: /sys/devices/.../power/wakeup_active_count
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_active_count attribute contains the
number of times the processing of wakeup events associated with
the device was completed (at the kernel level). This attribute
is read-only. If the device is not enabled to wake up the
system from sleep states, this attribute is empty.
What: /sys/devices/.../power/wakeup_hit_count
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_hit_count attribute contains the
number of times the processing of a wakeup event associated with
the device might prevent the system from entering a sleep state.
This attribute is read-only. If the device is not enabled to
wake up the system from sleep states, this attribute is empty.
What: /sys/devices/.../power/wakeup_active
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_active attribute contains either 1,
or 0, depending on whether or not a wakeup event associated with
the device is being processed (1). This attribute is read-only.
If the device is not enabled to wake up the system from sleep
states, this attribute is empty.
What: /sys/devices/.../power/wakeup_total_time_ms
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_total_time_ms attribute contains
the total time of processing wakeup events associated with the
device, in milliseconds. This attribute is read-only. If the
device is not enabled to wake up the system from sleep states,
this attribute is empty.
What: /sys/devices/.../power/wakeup_max_time_ms
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_max_time_ms attribute contains
the maximum time of processing a single wakeup event associated
with the device, in milliseconds. This attribute is read-only.
If the device is not enabled to wake up the system from sleep
states, this attribute is empty.
What: /sys/devices/.../power/wakeup_last_time_ms
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_last_time_ms attribute contains
the value of the monotonic clock corresponding to the time of
signaling the last wakeup event associated with the device, in
milliseconds. This attribute is read-only. If the device is
not enabled to wake up the system from sleep states, this
attribute is empty.
What: /sys/devices/.../power/autosuspend_delay_ms
Date: September 2010
Contact: Alan Stern <stern@rowland.harvard.edu>
Description:
The /sys/devices/.../power/autosuspend_delay_ms attribute
contains the autosuspend delay value (in milliseconds). Some
drivers do not want their device to suspend as soon as it
becomes idle at run time; they want the device to remain
inactive for a certain minimum period of time first. That
period is called the autosuspend delay. Negative values will
prevent the device from being suspended at run time (similar
to writing "on" to the power/control attribute). Values >=
1000 will cause the autosuspend timer expiration to be rounded
up to the nearest second.
Not all drivers support this attribute. If it isn't supported,
attempts to read or write it will yield I/O errors.
+29
View File
@@ -99,9 +99,38 @@ Description:
dmesg -s 1000000 | grep 'hash matches'
If you do not get any matches (or they appear to be false
positives), it is possible that the last PM event point
referred to a device created by a loadable kernel module. In
this case cat /sys/power/pm_trace_dev_match (see below) after
your system is started up and the kernel modules are loaded.
CAUTION: Using it will cause your machine's real-time (CMOS)
clock to be set to a random invalid time after a resume.
What; /sys/power/pm_trace_dev_match
Date: October 2010
Contact: James Hogan <james@albanarts.com>
Description:
The /sys/power/pm_trace_dev_match file contains the name of the
device associated with the last PM event point saved in the RTC
across reboots when pm_trace has been used. More precisely it
contains the list of current devices (including those
registered by loadable kernel modules since boot) which match
the device hash in the RTC at boot, with a newline after each
one.
The advantage of this file over the hash matches printed to the
kernel log (see /sys/power/pm_trace), is that it includes
devices created after boot by loadable kernel modules.
Due to the small hash size necessary to fit in the RTC, it is
possible that more than one device matches the hash, in which
case further investigation is required to determine which
device is causing the problem. Note that genuine RTC clock
values (such as when pm_trace has not been used), can still
match a device and output it's name here.
What: /sys/power/pm_async
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
+5
View File
@@ -2170,6 +2170,11 @@ and is between 256 and 4096 characters. It is defined in the file
in <PAGE_SIZE> units (needed only for swap files).
See Documentation/power/swsusp-and-swap-files.txt
hibernate= [HIBERNATION]
noresume Don't check if there's a hibernation image
present during boot.
nocompress Don't compress/decompress hibernation images.
retain_initrd [RAM] Keep initrd memory after extraction
rhash_entries= [KNL,NET]
+2
View File
@@ -14,6 +14,8 @@ interface.txt
- Power management user interface in /sys/power
notifiers.txt
- Registering suspend notifiers in device drivers
opp.txt
- Operating Performance Point library
pci.txt
- How the PCI Subsystem Does Power Management
pm_qos_interface.txt
+1 -1
View File
@@ -57,7 +57,7 @@ smallest image possible. In particular, if "0" is written to this file, the
suspend image will be as small as possible.
Reading from this file will display the current image size limit, which
is set to 500 MB by default.
is set to 2/5 of available RAM by default.
/sys/power/pm_trace controls the code which saves the last PM event point in
the RTC across reboots, so that you can debug a machine that just hangs
+375
View File
@@ -0,0 +1,375 @@
*=============*
* OPP Library *
*=============*
(C) 2009-2010 Nishanth Menon <nm@ti.com>, Texas Instruments Incorporated
Contents
--------
1. Introduction
2. Initial OPP List Registration
3. OPP Search Functions
4. OPP Availability Control Functions
5. OPP Data Retrieval Functions
6. Cpufreq Table Generation
7. Data Structures
1. Introduction
===============
Complex SoCs of today consists of a multiple sub-modules working in conjunction.
In an operational system executing varied use cases, not all modules in the SoC
need to function at their highest performing frequency all the time. To
facilitate this, sub-modules in a SoC are grouped into domains, allowing some
domains to run at lower voltage and frequency while other domains are loaded
more. The set of discrete tuples consisting of frequency and voltage pairs that
the device will support per domain are called Operating Performance Points or
OPPs.
OPP library provides a set of helper functions to organize and query the OPP
information. The library is located in drivers/base/power/opp.c and the header
is located in include/linux/opp.h. OPP library can be enabled by enabling
CONFIG_PM_OPP from power management menuconfig menu. OPP library depends on
CONFIG_PM as certain SoCs such as Texas Instrument's OMAP framework allows to
optionally boot at a certain OPP without needing cpufreq.
Typical usage of the OPP library is as follows:
(users) -> registers a set of default OPPs -> (library)
SoC framework -> modifies on required cases certain OPPs -> OPP layer
-> queries to search/retrieve information ->
OPP layer expects each domain to be represented by a unique device pointer. SoC
framework registers a set of initial OPPs per device with the OPP layer. This
list is expected to be an optimally small number typically around 5 per device.
This initial list contains a set of OPPs that the framework expects to be safely
enabled by default in the system.
Note on OPP Availability:
------------------------
As the system proceeds to operate, SoC framework may choose to make certain
OPPs available or not available on each device based on various external
factors. Example usage: Thermal management or other exceptional situations where
SoC framework might choose to disable a higher frequency OPP to safely continue
operations until that OPP could be re-enabled if possible.
OPP library facilitates this concept in it's implementation. The following
operational functions operate only on available opps:
opp_find_freq_{ceil, floor}, opp_get_voltage, opp_get_freq, opp_get_opp_count
and opp_init_cpufreq_table
opp_find_freq_exact is meant to be used to find the opp pointer which can then
be used for opp_enable/disable functions to make an opp available as required.
WARNING: Users of OPP library should refresh their availability count using
get_opp_count if opp_enable/disable functions are invoked for a device, the
exact mechanism to trigger these or the notification mechanism to other
dependent subsystems such as cpufreq are left to the discretion of the SoC
specific framework which uses the OPP library. Similar care needs to be taken
care to refresh the cpufreq table in cases of these operations.
WARNING on OPP List locking mechanism:
-------------------------------------------------
OPP library uses RCU for exclusivity. RCU allows the query functions to operate
in multiple contexts and this synchronization mechanism is optimal for a read
intensive operations on data structure as the OPP library caters to.
To ensure that the data retrieved are sane, the users such as SoC framework
should ensure that the section of code operating on OPP queries are locked
using RCU read locks. The opp_find_freq_{exact,ceil,floor},
opp_get_{voltage, freq, opp_count} fall into this category.
opp_{add,enable,disable} are updaters which use mutex and implement it's own
RCU locking mechanisms. opp_init_cpufreq_table acts as an updater and uses
mutex to implment RCU updater strategy. These functions should *NOT* be called
under RCU locks and other contexts that prevent blocking functions in RCU or
mutex operations from working.
2. Initial OPP List Registration
================================
The SoC implementation calls opp_add function iteratively to add OPPs per
device. It is expected that the SoC framework will register the OPP entries
optimally- typical numbers range to be less than 5. The list generated by
registering the OPPs is maintained by OPP library throughout the device
operation. The SoC framework can subsequently control the availability of the
OPPs dynamically using the opp_enable / disable functions.
opp_add - Add a new OPP for a specific domain represented by the device pointer.
The OPP is defined using the frequency and voltage. Once added, the OPP
is assumed to be available and control of it's availability can be done
with the opp_enable/disable functions. OPP library internally stores
and manages this information in the opp struct. This function may be
used by SoC framework to define a optimal list as per the demands of
SoC usage environment.
WARNING: Do not use this function in interrupt context.
Example:
soc_pm_init()
{
/* Do things */
r = opp_add(mpu_dev, 1000000, 900000);
if (!r) {
pr_err("%s: unable to register mpu opp(%d)\n", r);
goto no_cpufreq;
}
/* Do cpufreq things */
no_cpufreq:
/* Do remaining things */
}
3. OPP Search Functions
=======================
High level framework such as cpufreq operates on frequencies. To map the
frequency back to the corresponding OPP, OPP library provides handy functions
to search the OPP list that OPP library internally manages. These search
functions return the matching pointer representing the opp if a match is
found, else returns error. These errors are expected to be handled by standard
error checks such as IS_ERR() and appropriate actions taken by the caller.
opp_find_freq_exact - Search for an OPP based on an *exact* frequency and
availability. This function is especially useful to enable an OPP which
is not available by default.
Example: In a case when SoC framework detects a situation where a
higher frequency could be made available, it can use this function to
find the OPP prior to call the opp_enable to actually make it available.
rcu_read_lock();
opp = opp_find_freq_exact(dev, 1000000000, false);
rcu_read_unlock();
/* dont operate on the pointer.. just do a sanity check.. */
if (IS_ERR(opp)) {
pr_err("frequency not disabled!\n");
/* trigger appropriate actions.. */
} else {
opp_enable(dev,1000000000);
}
NOTE: This is the only search function that operates on OPPs which are
not available.
opp_find_freq_floor - Search for an available OPP which is *at most* the
provided frequency. This function is useful while searching for a lesser
match OR operating on OPP information in the order of decreasing
frequency.
Example: To find the highest opp for a device:
freq = ULONG_MAX;
rcu_read_lock();
opp_find_freq_floor(dev, &freq);
rcu_read_unlock();
opp_find_freq_ceil - Search for an available OPP which is *at least* the
provided frequency. This function is useful while searching for a
higher match OR operating on OPP information in the order of increasing
frequency.
Example 1: To find the lowest opp for a device:
freq = 0;
rcu_read_lock();
opp_find_freq_ceil(dev, &freq);
rcu_read_unlock();
Example 2: A simplified implementation of a SoC cpufreq_driver->target:
soc_cpufreq_target(..)
{
/* Do stuff like policy checks etc. */
/* Find the best frequency match for the req */
rcu_read_lock();
opp = opp_find_freq_ceil(dev, &freq);
rcu_read_unlock();
if (!IS_ERR(opp))
soc_switch_to_freq_voltage(freq);
else
/* do something when we cant satisfy the req */
/* do other stuff */
}
4. OPP Availability Control Functions
=====================================
A default OPP list registered with the OPP library may not cater to all possible
situation. The OPP library provides a set of functions to modify the
availability of a OPP within the OPP list. This allows SoC frameworks to have
fine grained dynamic control of which sets of OPPs are operationally available.
These functions are intended to *temporarily* remove an OPP in conditions such
as thermal considerations (e.g. don't use OPPx until the temperature drops).
WARNING: Do not use these functions in interrupt context.
opp_enable - Make a OPP available for operation.
Example: Lets say that 1GHz OPP is to be made available only if the
SoC temperature is lower than a certain threshold. The SoC framework
implementation might choose to do something as follows:
if (cur_temp < temp_low_thresh) {
/* Enable 1GHz if it was disabled */
rcu_read_lock();
opp = opp_find_freq_exact(dev, 1000000000, false);
rcu_read_unlock();
/* just error check */
if (!IS_ERR(opp))
ret = opp_enable(dev, 1000000000);
else
goto try_something_else;
}
opp_disable - Make an OPP to be not available for operation
Example: Lets say that 1GHz OPP is to be disabled if the temperature
exceeds a threshold value. The SoC framework implementation might
choose to do something as follows:
if (cur_temp > temp_high_thresh) {
/* Disable 1GHz if it was enabled */
rcu_read_lock();
opp = opp_find_freq_exact(dev, 1000000000, true);
rcu_read_unlock();
/* just error check */
if (!IS_ERR(opp))
ret = opp_disable(dev, 1000000000);
else
goto try_something_else;
}
5. OPP Data Retrieval Functions
===============================
Since OPP library abstracts away the OPP information, a set of functions to pull
information from the OPP structure is necessary. Once an OPP pointer is
retrieved using the search functions, the following functions can be used by SoC
framework to retrieve the information represented inside the OPP layer.
opp_get_voltage - Retrieve the voltage represented by the opp pointer.
Example: At a cpufreq transition to a different frequency, SoC
framework requires to set the voltage represented by the OPP using
the regulator framework to the Power Management chip providing the
voltage.
soc_switch_to_freq_voltage(freq)
{
/* do things */
rcu_read_lock();
opp = opp_find_freq_ceil(dev, &freq);
v = opp_get_voltage(opp);
rcu_read_unlock();
if (v)
regulator_set_voltage(.., v);
/* do other things */
}
opp_get_freq - Retrieve the freq represented by the opp pointer.
Example: Lets say the SoC framework uses a couple of helper functions
we could pass opp pointers instead of doing additional parameters to
handle quiet a bit of data parameters.
soc_cpufreq_target(..)
{
/* do things.. */
max_freq = ULONG_MAX;
rcu_read_lock();
max_opp = opp_find_freq_floor(dev,&max_freq);
requested_opp = opp_find_freq_ceil(dev,&freq);
if (!IS_ERR(max_opp) && !IS_ERR(requested_opp))
r = soc_test_validity(max_opp, requested_opp);
rcu_read_unlock();
/* do other things */
}
soc_test_validity(..)
{
if(opp_get_voltage(max_opp) < opp_get_voltage(requested_opp))
return -EINVAL;
if(opp_get_freq(max_opp) < opp_get_freq(requested_opp))
return -EINVAL;
/* do things.. */
}
opp_get_opp_count - Retrieve the number of available opps for a device
Example: Lets say a co-processor in the SoC needs to know the available
frequencies in a table, the main processor can notify as following:
soc_notify_coproc_available_frequencies()
{
/* Do things */
rcu_read_lock();
num_available = opp_get_opp_count(dev);
speeds = kzalloc(sizeof(u32) * num_available, GFP_KERNEL);
/* populate the table in increasing order */
freq = 0;
while (!IS_ERR(opp = opp_find_freq_ceil(dev, &freq))) {
speeds[i] = freq;
freq++;
i++;
}
rcu_read_unlock();
soc_notify_coproc(AVAILABLE_FREQs, speeds, num_available);
/* Do other things */
}
6. Cpufreq Table Generation
===========================
opp_init_cpufreq_table - cpufreq framework typically is initialized with
cpufreq_frequency_table_cpuinfo which is provided with the list of
frequencies that are available for operation. This function provides
a ready to use conversion routine to translate the OPP layer's internal
information about the available frequencies into a format readily
providable to cpufreq.
WARNING: Do not use this function in interrupt context.
Example:
soc_pm_init()
{
/* Do things */
r = opp_init_cpufreq_table(dev, &freq_table);
if (!r)
cpufreq_frequency_table_cpuinfo(policy, freq_table);
/* Do other things */
}
NOTE: This function is available only if CONFIG_CPU_FREQ is enabled in
addition to CONFIG_PM as power management feature is required to
dynamically scale voltage and frequency in a system.
7. Data Structures
==================
Typically an SoC contains multiple voltage domains which are variable. Each
domain is represented by a device pointer. The relationship to OPP can be
represented as follows:
SoC
|- device 1
| |- opp 1 (availability, freq, voltage)
| |- opp 2 ..
... ...
| `- opp n ..
|- device 2
...
`- device m
OPP library maintains a internal list that the SoC framework populates and
accessed by various functions as described above. However, the structures
representing the actual OPPs and domains are internal to the OPP library itself
to allow for suitable abstraction reusable across systems.
struct opp - The internal data structure of OPP library which is used to
represent an OPP. In addition to the freq, voltage, availability
information, it also contains internal book keeping information required
for the OPP library to operate on. Pointer to this structure is
provided back to the users such as SoC framework to be used as a
identifier for OPP in the interactions with OPP layer.
WARNING: The struct opp pointer should not be parsed or modified by the
users. The defaults of for an instance is populated by opp_add, but the
availability of the OPP can be modified by opp_enable/disable functions.
struct device - This is used to identify a domain to the OPP layer. The
nature of the device and it's implementation is left to the user of
OPP library such as the SoC framework.
Overall, in a simplistic view, the data structure operations is represented as
following:
Initialization / modification:
+-----+ /- opp_enable
opp_add --> | opp | <-------
| +-----+ \- opp_disable
\-------> domain_info(device)
Search functions:
/-- opp_find_freq_ceil ---\ +-----+
domain_info<---- opp_find_freq_exact -----> | opp |
\-- opp_find_freq_floor ---/ +-----+
Retrieval functions:
+-----+ /- opp_get_voltage
| opp | <---
+-----+ \- opp_get_freq
domain_info <- opp_get_opp_count
+220 -7
View File
@@ -1,6 +1,7 @@
Run-time Power Management Framework for I/O Devices
(C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
(C) 2010 Alan Stern <stern@rowland.harvard.edu>
1. Introduction
@@ -157,7 +158,8 @@ rules:
to execute it, the other callbacks will not be executed for the same device.
* A request to execute ->runtime_resume() will cancel any pending or
scheduled requests to execute the other callbacks for the same device.
scheduled requests to execute the other callbacks for the same device,
except for scheduled autosuspends.
3. Run-time PM Device Fields
@@ -165,7 +167,7 @@ The following device run-time PM fields are present in 'struct dev_pm_info', as
defined in include/linux/pm.h:
struct timer_list suspend_timer;
- timer used for scheduling (delayed) suspend request
- timer used for scheduling (delayed) suspend and autosuspend requests
unsigned long timer_expires;
- timer expiration time, in jiffies (if this is different from zero, the
@@ -230,6 +232,28 @@ defined in include/linux/pm.h:
interface; it may only be modified with the help of the pm_runtime_allow()
and pm_runtime_forbid() helper functions
unsigned int no_callbacks;
- indicates that the device does not use the run-time PM callbacks (see
Section 8); it may be modified only by the pm_runtime_no_callbacks()
helper function
unsigned int use_autosuspend;
- indicates that the device's driver supports delayed autosuspend (see
Section 9); it may be modified only by the
pm_runtime{_dont}_use_autosuspend() helper functions
unsigned int timer_autosuspends;
- indicates that the PM core should attempt to carry out an autosuspend
when the timer expires rather than a normal suspend
int autosuspend_delay;
- the delay time (in milliseconds) to be used for autosuspend
unsigned long last_busy;
- the time (in jiffies) when the pm_runtime_mark_last_busy() helper
function was last called for this device; used in calculating inactivity
periods for autosuspend
All of the above fields are members of the 'power' member of 'struct device'.
4. Run-time PM Device Helper Functions
@@ -255,6 +279,12 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
error code on failure, where -EAGAIN or -EBUSY means it is safe to attempt
to suspend the device again in future
int pm_runtime_autosuspend(struct device *dev);
- same as pm_runtime_suspend() except that the autosuspend delay is taken
into account; if pm_runtime_autosuspend_expiration() says the delay has
not yet expired then an autosuspend is scheduled for the appropriate time
and 0 is returned
int pm_runtime_resume(struct device *dev);
- execute the subsystem-level resume callback for the device; returns 0 on
success, 1 if the device's run-time PM status was already 'active' or
@@ -267,6 +297,11 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
device (the request is represented by a work item in pm_wq); returns 0 on
success or error code if the request has not been queued up
int pm_request_autosuspend(struct device *dev);
- schedule the execution of the subsystem-level suspend callback for the
device when the autosuspend delay has expired; if the delay has already
expired then the work item is queued up immediately
int pm_schedule_suspend(struct device *dev, unsigned int delay);
- schedule the execution of the subsystem-level suspend callback for the
device in future, where 'delay' is the time to wait before queuing up a
@@ -298,12 +333,20 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
- decrement the device's usage counter
int pm_runtime_put(struct device *dev);
- decrement the device's usage counter, run pm_request_idle(dev) and return
its result
- decrement the device's usage counter; if the result is 0 then run
pm_request_idle(dev) and return its result
int pm_runtime_put_autosuspend(struct device *dev);
- decrement the device's usage counter; if the result is 0 then run
pm_request_autosuspend(dev) and return its result
int pm_runtime_put_sync(struct device *dev);
- decrement the device's usage counter, run pm_runtime_idle(dev) and return
its result
- decrement the device's usage counter; if the result is 0 then run
pm_runtime_idle(dev) and return its result
int pm_runtime_put_sync_autosuspend(struct device *dev);
- decrement the device's usage counter; if the result is 0 then run
pm_runtime_autosuspend(dev) and return its result
void pm_runtime_enable(struct device *dev);
- enable the run-time PM helper functions to run the device bus type's
@@ -349,19 +392,51 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
counter (used by the /sys/devices/.../power/control interface to
effectively prevent the device from being power managed at run time)
void pm_runtime_no_callbacks(struct device *dev);
- set the power.no_callbacks flag for the device and remove the run-time
PM attributes from /sys/devices/.../power (or prevent them from being
added when the device is registered)
void pm_runtime_mark_last_busy(struct device *dev);
- set the power.last_busy field to the current time
void pm_runtime_use_autosuspend(struct device *dev);
- set the power.use_autosuspend flag, enabling autosuspend delays
void pm_runtime_dont_use_autosuspend(struct device *dev);
- clear the power.use_autosuspend flag, disabling autosuspend delays
void pm_runtime_set_autosuspend_delay(struct device *dev, int delay);
- set the power.autosuspend_delay value to 'delay' (expressed in
milliseconds); if 'delay' is negative then run-time suspends are
prevented
unsigned long pm_runtime_autosuspend_expiration(struct device *dev);
- calculate the time when the current autosuspend delay period will expire,
based on power.last_busy and power.autosuspend_delay; if the delay time
is 1000 ms or larger then the expiration time is rounded up to the
nearest second; returns 0 if the delay period has already expired or
power.use_autosuspend isn't set, otherwise returns the expiration time
in jiffies
It is safe to execute the following helper functions from interrupt context:
pm_request_idle()
pm_request_autosuspend()
pm_schedule_suspend()
pm_request_resume()
pm_runtime_get_noresume()
pm_runtime_get()
pm_runtime_put_noidle()
pm_runtime_put()
pm_runtime_put_autosuspend()
pm_runtime_enable()
pm_suspend_ignore_children()
pm_runtime_set_active()
pm_runtime_set_suspended()
pm_runtime_enable()
pm_runtime_suspended()
pm_runtime_mark_last_busy()
pm_runtime_autosuspend_expiration()
5. Run-time PM Initialization, Device Probing and Removal
@@ -524,3 +599,141 @@ poweroff and run-time suspend callback, and similarly for system resume, thaw,
restore, and run-time resume, can achieve this with the help of the
UNIVERSAL_DEV_PM_OPS macro defined in include/linux/pm.h (possibly setting its
last argument to NULL).
8. "No-Callback" Devices
Some "devices" are only logical sub-devices of their parent and cannot be
power-managed on their own. (The prototype example is a USB interface. Entire
USB devices can go into low-power mode or send wake-up requests, but neither is
possible for individual interfaces.) The drivers for these devices have no
need of run-time PM callbacks; if the callbacks did exist, ->runtime_suspend()
and ->runtime_resume() would always return 0 without doing anything else and
->runtime_idle() would always call pm_runtime_suspend().
Subsystems can tell the PM core about these devices by calling
pm_runtime_no_callbacks(). This should be done after the device structure is
initialized and before it is registered (although after device registration is
also okay). The routine will set the device's power.no_callbacks flag and
prevent the non-debugging run-time PM sysfs attributes from being created.
When power.no_callbacks is set, the PM core will not invoke the
->runtime_idle(), ->runtime_suspend(), or ->runtime_resume() callbacks.
Instead it will assume that suspends and resumes always succeed and that idle
devices should be suspended.
As a consequence, the PM core will never directly inform the device's subsystem
or driver about run-time power changes. Instead, the driver for the device's
parent must take responsibility for telling the device's driver when the
parent's power state changes.
9. Autosuspend, or automatically-delayed suspends
Changing a device's power state isn't free; it requires both time and energy.
A device should be put in a low-power state only when there's some reason to
think it will remain in that state for a substantial time. A common heuristic
says that a device which hasn't been used for a while is liable to remain
unused; following this advice, drivers should not allow devices to be suspended
at run-time until they have been inactive for some minimum period. Even when
the heuristic ends up being non-optimal, it will still prevent devices from
"bouncing" too rapidly between low-power and full-power states.
The term "autosuspend" is an historical remnant. It doesn't mean that the
device is automatically suspended (the subsystem or driver still has to call
the appropriate PM routines); rather it means that run-time suspends will
automatically be delayed until the desired period of inactivity has elapsed.
Inactivity is determined based on the power.last_busy field. Drivers should
call pm_runtime_mark_last_busy() to update this field after carrying out I/O,
typically just before calling pm_runtime_put_autosuspend(). The desired length
of the inactivity period is a matter of policy. Subsystems can set this length
initially by calling pm_runtime_set_autosuspend_delay(), but after device
registration the length should be controlled by user space, using the
/sys/devices/.../power/autosuspend_delay_ms attribute.
In order to use autosuspend, subsystems or drivers must call
pm_runtime_use_autosuspend() (preferably before registering the device), and
thereafter they should use the various *_autosuspend() helper functions instead
of the non-autosuspend counterparts:
Instead of: pm_runtime_suspend use: pm_runtime_autosuspend;
Instead of: pm_schedule_suspend use: pm_request_autosuspend;
Instead of: pm_runtime_put use: pm_runtime_put_autosuspend;
Instead of: pm_runtime_put_sync use: pm_runtime_put_sync_autosuspend.
Drivers may also continue to use the non-autosuspend helper functions; they
will behave normally, not taking the autosuspend delay into account.
Similarly, if the power.use_autosuspend field isn't set then the autosuspend
helper functions will behave just like the non-autosuspend counterparts.
The implementation is well suited for asynchronous use in interrupt contexts.
However such use inevitably involves races, because the PM core can't
synchronize ->runtime_suspend() callbacks with the arrival of I/O requests.
This synchronization must be handled by the driver, using its private lock.
Here is a schematic pseudo-code example:
foo_read_or_write(struct foo_priv *foo, void *data)
{
lock(&foo->private_lock);
add_request_to_io_queue(foo, data);
if (foo->num_pending_requests++ == 0)
pm_runtime_get(&foo->dev);
if (!foo->is_suspended)
foo_process_next_request(foo);
unlock(&foo->private_lock);
}
foo_io_completion(struct foo_priv *foo, void *req)
{
lock(&foo->private_lock);
if (--foo->num_pending_requests == 0) {
pm_runtime_mark_last_busy(&foo->dev);
pm_runtime_put_autosuspend(&foo->dev);
} else {
foo_process_next_request(foo);
}
unlock(&foo->private_lock);
/* Send req result back to the user ... */
}
int foo_runtime_suspend(struct device *dev)
{
struct foo_priv foo = container_of(dev, ...);
int ret = 0;
lock(&foo->private_lock);
if (foo->num_pending_requests > 0) {
ret = -EBUSY;
} else {
/* ... suspend the device ... */
foo->is_suspended = 1;
}
unlock(&foo->private_lock);
return ret;
}
int foo_runtime_resume(struct device *dev)
{
struct foo_priv foo = container_of(dev, ...);
lock(&foo->private_lock);
/* ... resume the device ... */
foo->is_suspended = 0;
pm_runtime_mark_last_busy(&foo->dev);
if (foo->num_pending_requests > 0)
foo_process_requests(foo);
unlock(&foo->private_lock);
return 0;
}
The important point is that after foo_io_completion() asks for an autosuspend,
the foo_runtime_suspend() callback may race with foo_read_or_write().
Therefore foo_runtime_suspend() has to check whether there are any pending I/O
requests (while holding the private lock) before allowing the suspend to
proceed.
In addition, the power.autosuspend_delay field can be changed by user space at
any time. If a driver cares about this, it can call
pm_runtime_autosuspend_expiration() from within the ->runtime_suspend()
callback while holding its private lock. If the function returns a nonzero
value then the delay has not yet expired and the callback should return
-EAGAIN.
+7
View File
@@ -49,6 +49,13 @@ machine that doesn't boot) is:
device (lspci and /sys/devices/pci* is your friend), and see if you can
fix it, disable it, or trace into its resume function.
If no device matches the hash (or any matches appear to be false positives),
the culprit may be a device from a loadable kernel module that is not loaded
until after the hash is checked. You can check the hash against the current
devices again after more modules are loaded using sysfs:
cat /sys/power/pm_trace_dev_match
For example, the above happens to be the VGA device on my EVO, which I
used to run with "radeonfb" (it's an ATI Radeon mobility). It turns out
that "radeonfb" simply cannot resume that device - it tries to set the
+2 -1
View File
@@ -66,7 +66,8 @@ swsusp saves the state of the machine into active swaps and then reboots or
powerdowns. You must explicitly specify the swap partition to resume from with
``resume='' kernel option. If signature is found it loads and restores saved
state. If the option ``noresume'' is specified as a boot parameter, it skips
the resuming.
the resuming. If the option ``hibernate=nocompress'' is specified as a boot
parameter, it saves hibernation image without compression.
In the meantime while the system is suspended you should not add/remove any
of the hardware, write to the filesystems, etc.
+1
View File
@@ -3,6 +3,7 @@ obj-$(CONFIG_PM_SLEEP) += main.o wakeup.o
obj-$(CONFIG_PM_RUNTIME) += runtime.o
obj-$(CONFIG_PM_OPS) += generic_ops.o
obj-$(CONFIG_PM_TRACE_RTC) += trace.o
obj-$(CONFIG_PM_OPP) += opp.o
ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
ccflags-$(CONFIG_PM_VERBOSE) += -DDEBUG
+2 -2
View File
@@ -46,7 +46,7 @@ int pm_generic_runtime_suspend(struct device *dev)
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int ret;
ret = pm && pm->runtime_suspend ? pm->runtime_suspend(dev) : -EINVAL;
ret = pm && pm->runtime_suspend ? pm->runtime_suspend(dev) : 0;
return ret;
}
@@ -65,7 +65,7 @@ int pm_generic_runtime_resume(struct device *dev)
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int ret;
ret = pm && pm->runtime_resume ? pm->runtime_resume(dev) : -EINVAL;
ret = pm && pm->runtime_resume ? pm->runtime_resume(dev) : 0;
return ret;
}
+13 -8
View File
@@ -51,6 +51,8 @@ static pm_message_t pm_transition;
*/
static bool transition_started;
static int async_error;
/**
* device_pm_init - Initialize the PM-related part of a device object.
* @dev: Device object being initialized.
@@ -60,7 +62,8 @@ void device_pm_init(struct device *dev)
dev->power.status = DPM_ON;
init_completion(&dev->power.completion);
complete_all(&dev->power.completion);
dev->power.wakeup_count = 0;
dev->power.wakeup = NULL;
spin_lock_init(&dev->power.lock);
pm_runtime_init(dev);
}
@@ -120,6 +123,7 @@ void device_pm_remove(struct device *dev)
mutex_lock(&dpm_list_mtx);
list_del_init(&dev->power.entry);
mutex_unlock(&dpm_list_mtx);
device_wakeup_disable(dev);
pm_runtime_remove(dev);
}
@@ -407,7 +411,7 @@ static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
{
ktime_t calltime;
s64 usecs64;
u64 usecs64;
int usecs;
calltime = ktime_get();
@@ -600,6 +604,7 @@ static void dpm_resume(pm_message_t state)
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
pm_transition = state;
async_error = 0;
list_for_each_entry(dev, &dpm_list, power.entry) {
if (dev->power.status < DPM_OFF)
@@ -829,8 +834,6 @@ static int legacy_suspend(struct device *dev, pm_message_t state,
return error;
}
static int async_error;
/**
* device_suspend - Execute "suspend" callbacks for given device.
* @dev: Device to handle.
@@ -885,6 +888,9 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
device_unlock(dev);
complete_all(&dev->power.completion);
if (error)
async_error = error;
return error;
}
@@ -894,10 +900,8 @@ static void async_suspend(void *data, async_cookie_t cookie)
int error;
error = __device_suspend(dev, pm_transition, true);
if (error) {
if (error)
pm_dev_err(dev, pm_transition, " async", error);
async_error = error;
}
put_device(dev);
}
@@ -1085,8 +1089,9 @@ EXPORT_SYMBOL_GPL(__suspend_report_result);
* @dev: Device to wait for.
* @subordinate: Device that needs to wait for @dev.
*/
void device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
{
dpm_wait(dev, subordinate->power.async_suspend);
return async_error;
}
EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
File diff suppressed because it is too large Load Diff
+2
View File
@@ -34,6 +34,7 @@ extern void device_pm_move_last(struct device *);
static inline void device_pm_init(struct device *dev)
{
spin_lock_init(&dev->power.lock);
pm_runtime_init(dev);
}
@@ -59,6 +60,7 @@ static inline void device_pm_move_last(struct device *dev) {}
extern int dpm_sysfs_add(struct device *);
extern void dpm_sysfs_remove(struct device *);
extern void rpm_sysfs_remove(struct device *);
#else /* CONFIG_PM */
File diff suppressed because it is too large Load Diff
+208 -9
View File
@@ -75,12 +75,27 @@
* 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.
*
* 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().
*
* wakeup_count - Report the number of wakeup events related to the device
*/
static const char enabled[] = "enabled";
static const char disabled[] = "disabled";
const char power_group_name[] = "power";
EXPORT_SYMBOL_GPL(power_group_name);
#ifdef CONFIG_PM_RUNTIME
static const char ctrl_auto[] = "auto";
static const char ctrl_on[] = "on";
@@ -170,6 +185,33 @@ static ssize_t rtpm_status_show(struct device *dev,
}
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 (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
return -EINVAL;
pm_runtime_set_autosuspend_delay(dev, delay);
return n;
}
static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
autosuspend_delay_ms_store);
#endif
static ssize_t
@@ -210,11 +252,122 @@ static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
static ssize_t wakeup_count_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%lu\n", dev->power.wakeup_count);
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");
}
static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
#endif
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_hit_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->hit_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_hit_count, 0444, wakeup_hit_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);
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_PM_ADVANCED_DEBUG
#ifdef CONFIG_PM_RUNTIME
@@ -279,19 +432,20 @@ static DEVICE_ATTR(async, 0644, async_show, async_store);
#endif /* CONFIG_PM_ADVANCED_DEBUG */
static struct attribute * power_attrs[] = {
#ifdef CONFIG_PM_RUNTIME
&dev_attr_control.attr,
&dev_attr_runtime_status.attr,
&dev_attr_runtime_suspended_time.attr,
&dev_attr_runtime_active_time.attr,
#endif
&dev_attr_wakeup.attr,
#ifdef CONFIG_PM_SLEEP
&dev_attr_wakeup_count.attr,
&dev_attr_wakeup_active_count.attr,
&dev_attr_wakeup_hit_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,
#endif
#ifdef CONFIG_PM_ADVANCED_DEBUG
&dev_attr_async.attr,
#ifdef CONFIG_PM_RUNTIME
&dev_attr_runtime_status.attr,
&dev_attr_runtime_usage.attr,
&dev_attr_runtime_active_kids.attr,
&dev_attr_runtime_enabled.attr,
@@ -300,10 +454,53 @@ static struct attribute * power_attrs[] = {
NULL,
};
static struct attribute_group pm_attr_group = {
.name = "power",
.name = power_group_name,
.attrs = power_attrs,
};
#ifdef CONFIG_PM_RUNTIME
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 struct attribute_group pm_runtime_attr_group = {
.name = power_group_name,
.attrs = runtime_attrs,
};
int dpm_sysfs_add(struct device *dev)
{
int rc;
rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
if (rc == 0 && !dev->power.no_callbacks) {
rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
if (rc)
sysfs_remove_group(&dev->kobj, &pm_attr_group);
}
return rc;
}
void rpm_sysfs_remove(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
}
void dpm_sysfs_remove(struct device *dev)
{
rpm_sysfs_remove(dev);
sysfs_remove_group(&dev->kobj, &pm_attr_group);
}
#else /* CONFIG_PM_RUNTIME */
int dpm_sysfs_add(struct device * dev)
{
return sysfs_create_group(&dev->kobj, &pm_attr_group);
@@ -313,3 +510,5 @@ void dpm_sysfs_remove(struct device * dev)
{
sysfs_remove_group(&dev->kobj, &pm_attr_group);
}
#endif
+35 -1
View File
@@ -188,8 +188,10 @@ static int show_file_hash(unsigned int value)
static int show_dev_hash(unsigned int value)
{
int match = 0;
struct list_head *entry = dpm_list.prev;
struct list_head *entry;
device_pm_lock();
entry = dpm_list.prev;
while (entry != &dpm_list) {
struct device * dev = to_device(entry);
unsigned int hash = hash_string(DEVSEED, dev_name(dev), DEVHASH);
@@ -199,11 +201,43 @@ static int show_dev_hash(unsigned int value)
}
entry = entry->prev;
}
device_pm_unlock();
return match;
}
static unsigned int hash_value_early_read;
int show_trace_dev_match(char *buf, size_t size)
{
unsigned int value = hash_value_early_read / (USERHASH * FILEHASH);
int ret = 0;
struct list_head *entry;
/*
* It's possible that multiple devices will match the hash and we can't
* tell which is the culprit, so it's best to output them all.
*/
device_pm_lock();
entry = dpm_list.prev;
while (size && entry != &dpm_list) {
struct device *dev = to_device(entry);
unsigned int hash = hash_string(DEVSEED, dev_name(dev),
DEVHASH);
if (hash == value) {
int len = snprintf(buf, size, "%s\n",
dev_driver_string(dev));
if (len > size)
len = size;
buf += len;
ret += len;
size -= len;
}
entry = entry->prev;
}
device_pm_unlock();
return ret;
}
static int early_resume_init(void)
{
hash_value_early_read = read_magic_time();
File diff suppressed because it is too large Load Diff
+59
View File
@@ -148,6 +148,65 @@ void sysfs_remove_group(struct kobject * kobj,
sysfs_put(sd);
}
/**
* sysfs_merge_group - merge files into a pre-existing attribute group.
* @kobj: The kobject containing the group.
* @grp: The files to create and the attribute group they belong to.
*
* This function returns an error if the group doesn't exist or any of the
* files already exist in that group, in which case none of the new files
* are created.
*/
int sysfs_merge_group(struct kobject *kobj,
const struct attribute_group *grp)
{
struct sysfs_dirent *dir_sd;
int error = 0;
struct attribute *const *attr;
int i;
if (grp)
dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name);
else
dir_sd = sysfs_get(kobj->sd);
if (!dir_sd)
return -ENOENT;
for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
if (error) {
while (--i >= 0)
sysfs_hash_and_remove(dir_sd, NULL, (*--attr)->name);
}
sysfs_put(dir_sd);
return error;
}
EXPORT_SYMBOL_GPL(sysfs_merge_group);
/**
* sysfs_unmerge_group - remove files from a pre-existing attribute group.
* @kobj: The kobject containing the group.
* @grp: The files to remove and the attribute group they belong to.
*/
void sysfs_unmerge_group(struct kobject *kobj,
const struct attribute_group *grp)
{
struct sysfs_dirent *dir_sd;
struct attribute *const *attr;
if (grp)
dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name);
else
dir_sd = sysfs_get(kobj->sd);
if (dir_sd) {
for (attr = grp->attrs; *attr; ++attr)
sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
sysfs_put(dir_sd);
}
}
EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
EXPORT_SYMBOL_GPL(sysfs_create_group);
EXPORT_SYMBOL_GPL(sysfs_update_group);
+105
View File
@@ -0,0 +1,105 @@
/*
* Generic OPP Interface
*
* Copyright (C) 2009-2010 Texas Instruments Incorporated.
* Nishanth Menon
* Romit Dasgupta
* Kevin Hilman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __LINUX_OPP_H__
#define __LINUX_OPP_H__
#include <linux/err.h>
#include <linux/cpufreq.h>
struct opp;
#if defined(CONFIG_PM_OPP)
unsigned long opp_get_voltage(struct opp *opp);
unsigned long opp_get_freq(struct opp *opp);
int opp_get_opp_count(struct device *dev);
struct opp *opp_find_freq_exact(struct device *dev, unsigned long freq,
bool available);
struct opp *opp_find_freq_floor(struct device *dev, unsigned long *freq);
struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq);
int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt);
int opp_enable(struct device *dev, unsigned long freq);
int opp_disable(struct device *dev, unsigned long freq);
#else
static inline unsigned long opp_get_voltage(struct opp *opp)
{
return 0;
}
static inline unsigned long opp_get_freq(struct opp *opp)
{
return 0;
}
static inline int opp_get_opp_count(struct device *dev)
{
return 0;
}
static inline struct opp *opp_find_freq_exact(struct device *dev,
unsigned long freq, bool available)
{
return ERR_PTR(-EINVAL);
}
static inline struct opp *opp_find_freq_floor(struct device *dev,
unsigned long *freq)
{
return ERR_PTR(-EINVAL);
}
static inline struct opp *opp_find_freq_ceil(struct device *dev,
unsigned long *freq)
{
return ERR_PTR(-EINVAL);
}
static inline int opp_add(struct device *dev, unsigned long freq,
unsigned long u_volt)
{
return -EINVAL;
}
static inline int opp_enable(struct device *dev, unsigned long freq)
{
return 0;
}
static inline int opp_disable(struct device *dev, unsigned long freq)
{
return 0;
}
#endif /* CONFIG_PM */
#if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
int opp_init_cpufreq_table(struct device *dev,
struct cpufreq_frequency_table **table);
#else
static inline int opp_init_cpufreq_table(struct device *dev,
struct cpufreq_frequency_table **table)
{
return -EINVAL;
}
#endif /* CONFIG_CPU_FREQ */
#endif /* __LINUX_OPP_H__ */

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