Commit Graph

141 Commits

Author SHA1 Message Date
Chanwoo Choi
96ffcdf239 PM / devfreq: Remove redundant governor_name from struct devfreq
The devfreq structure instance contains the governor_name and a governor
instance. When need to show the governor name, better to use the name
of devfreq_governor structure. So, governor_name variable in struct devfreq
is a redundant and unneeded variable. Remove the redundant governor_name
of struct devfreq and then use the name of devfreq_governor instance.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 11:50:51 +09:00
Chanwoo Choi
5f1a9066fc PM / devfreq: Add governor attribute flag for specifc sysfs nodes
DEVFREQ supports the default governors like performance, simple_ondemand and
also allows the devfreq driver to add their own governor like tegra30-devfreq.c
according to their requirement. In result, some sysfs attributes are useful
or not useful. Prior to that the user can access all sysfs attributes
regardless of the available attributes.

So, clarify the access permission of sysfs attributes according to governor.
When adding the devfreq governor, can specify the available attribute
information by using DEVFREQ_GOV_ATTR_* constant variable. The user can
read or write the sysfs attributes in accordance to the specified attributes.

When adding the governor, can add the following attributes
according to the governor feature.

[Definition for speific sysfs attributes]
- DEVFREQ_GOV_ATTR_POLLING_INTERVAL to update polling interval for timer.
  : /sys/class/devfreq/[devfreq dev name]/polling_interval
- DEVFREQ_GOV_ATTR_TIMER to change the type of timer on either deferrable
  or dealyed timer.
  : /sys/class/devfreq/[devfreq dev name]/timer

And all devfreq governors have to support the following common attributes.
The common attributes are added to devfreq class by default.
- governor
- available_governors
- available_frequencies
- cur_freq
- target_freq
- min_freq
- max_freq
- trans_stat

[Table of governor attribute flags for devfreq governors]
------------------------------------------------------------------------------
                      | simple    | perfor | power | user | passive | tegra30
		      | ondemand  | mance  | save  | space|         |
------------------------------------------------------------------------------
governor              | O         | O      | O     | O    | O       | O
available_governors   | O         | O      | O     | O    | O       | O
available_frequencies | O         | O      | O     | O    | O       | O
cur_freq              | O         | O      | O     | O    | O       | O
target_freq           | O         | O      | O     | O    | O       | O
min_freq              | O         | O      | O     | O    | O       | O
max_freq              | O         | O      | O     | O    | O       | O
trans_stat            | O         | O      | O     | O    | O       | O
                      --------------------------------------------------------
polling_interval      | O         | X      | X     | X    | X       | O
timer                 | O         | X      | X     | X    | X       | X
------------------------------------------------------------------------------

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 11:46:54 +09:00
Chanwoo Choi
0dd25a0d12 PM / devfreq: Add governor feature flag
The devfreq governor is able to have the specific flag as follows
in order to implement the specific feature. For example, devfreq allows
user to change the governors on runtime via sysfs interface.
But, if devfreq device uses 'passive' governor, don't allow user to change
the governor. For this case, define the DEVFREQ_GOV_FLAG_IMMUTABLE
and set it to flag of passive governor.

[Definition for governor flag]
- DEVFREQ_GOV_FLAG_IMMUTABLE
  : If immutable flag is set, governor is never changeable to other governors.
- DEVFREQ_GOV_FLAG_IRQ_DRIVEN
  : Devfreq core won't schedule polling work for this governor if value is set.

[Table of governor flag for devfreq governors]
------------------------------------------------------------------------------
                      | simple    | perfor | power | user | passive | tegra30
		      | ondemand  | mance  | save  | space|         |
------------------------------------------------------------------------------
immutable             | X         | X      | X     | X    | O       | O
interrupt_driven      | X(polling)| X      | X     | X    | X       | O (irq)
------------------------------------------------------------------------------

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 10:54:41 +09:00
Matthias Kaehlcke
cab477d0d4 PM / devfreq: Add tracepoint for frequency changes
Add a tracepoint for frequency changes of devfreq devices and
use it.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
[cw00.choi: Move print position of tracepoint and add more information]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 10:52:37 +09:00
Chanwoo Choi
b4365423bb PM / devfreq: Unify frequency change to devfreq_update_target func
The update_devfreq() and update_passive_devfreq() have the duplicate
code when changing the target frequency on final stage. So, unify
frequency change code to devfreq_update_target() to remove the
duplicate code and to centralize the frequency change code.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 10:52:37 +09:00
Chanwoo Choi
86d90fd95b PM / devfreq: Change prototype of devfreq_get_devfreq_by_phandle function
Previously, devfreq core support 'devfreq' property in order to get
the devfreq device by phandle. But, 'devfreq' property name is not proper
on devicetree binding because this name doesn't mean the any h/w attribute.

The devfreq core hand over the right to decide the property name
for getting the devfreq device on devicetree. Each devfreq driver
will decide the property name on devicetree binding and pass
the their own property name to devfreq_get_devfreq_by_phandle function.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-29 17:50:10 +09:00
Leonard Crestez
7b38b7b042 PM / devfreq: Add devfreq_get_devfreq_by_node function
Split off part of devfreq_get_devfreq_by_phandle into a separate
function. This allows callers to fetch devfreq instances by enumerating
devicetree instead of explicit phandles.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
[cw00.choi: Export devfreq_get_devfreq_by_node function and
 add function to devfreq.h when CONFIG_PM_DEVFREQ is enabled.]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-29 17:50:09 +09:00
Chanwoo Choi
0c309ed17c PM / devfreq: Add timer type to devfreq_summary debugfs
The commit 4dc3bab868 ("PM / devfreq: Add support delayed timer for
polling mode") supports the delayed timer but this commit missed
the adding the timer type to devfreq_summary debugfs node.
Add the timer type to devfreq_summary debugfs.

Fixes: 4dc3bab868 ("PM / devfreq: Add support delayed timer for polling mode")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-23 13:35:58 +09:00
Chanwoo Choi
27a6971445 PM / devfreq: Fix the wrong end with semicolon
Fix the wrong grammar at the end of code line by using semicolon.

Cc: stable vger.kernel.org
Fixes: 490a421bc5 ("PM / devfreq: Add debugfs support with devfreq_summary file")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:58 +09:00
Chanwoo Choi
0aae11bcde PM / devfreq: Fix indentaion of devfreq_summary debugfs node
The commit 66d0e797bf ("Revert "PM / devfreq: Modify the device name
as devfreq(X) for sysfs"") roll back the device name from 'devfreqX'
to device name explained in DT. After applied commit 66d0e797bf,
the indentation of devfreq_summary debugfs node was broken.

So, fix indentaion of devfreq_summary debugfs node as following:

For example on Exynos5422-based Odroid-XU3 board,
$ cat /sys/kernel/debug/devfreq/devfreq_summary
dev                            parent_dev                     governor        polling_ms  cur_freq_Hz  min_freq_Hz  max_freq_Hz
------------------------------ ------------------------------ --------------- ---------- ------------ ------------ ------------
10c20000.memory-controller     null                           simple_ondemand          0    413000000    165000000    825000000
soc:bus_wcore                  null                           simple_ondemand         50     88700000     88700000    532000000
soc:bus_noc                    soc:bus_wcore                  passive                  0     66600000     66600000    111000000
soc:bus_fsys_apb               soc:bus_wcore                  passive                  0    111000000    111000000    222000000
soc:bus_fsys                   soc:bus_wcore                  passive                  0     75000000     75000000    200000000
soc:bus_fsys2                  soc:bus_wcore                  passive                  0     75000000     75000000    200000000
soc:bus_mfc                    soc:bus_wcore                  passive                  0     83250000     83250000    333000000
soc:bus_gen                    soc:bus_wcore                  passive                  0     88700000     88700000    266000000
soc:bus_peri                   soc:bus_wcore                  passive                  0     66600000     66600000     66600000
soc:bus_g2d                    soc:bus_wcore                  passive                  0     83250000     83250000    333000000
soc:bus_g2d_acp                soc:bus_wcore                  passive                  0            0     66500000    266000000
soc:bus_jpeg                   soc:bus_wcore                  passive                  0            0     75000000    300000000
soc:bus_jpeg_apb               soc:bus_wcore                  passive                  0            0     83250000    166500000
soc:bus_disp1_fimd             soc:bus_wcore                  passive                  0            0    120000000    200000000
soc:bus_disp1                  soc:bus_wcore                  passive                  0            0    120000000    300000000
soc:bus_gscl_scaler            soc:bus_wcore                  passive                  0            0    150000000    300000000
soc:bus_mscl                   soc:bus_wcore                  passive                  0            0     84000000    666000000

Cc: stable@vger.kernel.org
Fixes: 66d0e797bf ("Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs"")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:58 +09:00
Chanwoo Choi
483d557ee9 PM / devfreq: Clean up the devfreq instance name in sysfs attr
The sysfs attr interface used eithere 'df' or 'devfreq' for devfreq instance
name. In order to keep the consistency and to improve the readabilty,
unify the instance name as 'df'. Add add the missing conditional statement
to prevent the fault.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:57 +09:00
Chanwoo Choi
4dc3bab868 PM / devfreq: Add support delayed timer for polling mode
Until now, the devfreq driver using polling mode like simple_ondemand
governor have used only deferrable timer for reducing the redundant
power consumption. It reduces the CPU wake-up from idle due to polling mode
which check the status of Non-CPU device.

But, it has a problem for Non-CPU device like DMC device with DMA operation.
Some Non-CPU device need to do monitor continuously regardless of CPU state
in order to decide the proper next status of Non-CPU device.

So, add support the delayed timer for polling mode to support
the repetitive monitoring. The devfreq driver and user can select
the kind of timer on either deferrable and delayed timer.

For example, change the timer type of DMC device
based on Exynos5422-based Odroid-XU3 as following:

- If want to use deferrable timer as following:
echo deferrable > /sys/class/devfreq/10c20000.memory-controller/timer

- If want to use delayed timer as following:
echo delayed > /sys/class/devfreq/10c20000.memory-controller/timer

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:57 +09:00
Krzysztof Kozlowski
8fc0e48e0f PM / devfreq: Use lockdep asserts instead of manual checks for locked mutex
Instead of warning when mutex_is_locked(), just use the lockdep
framework.  The code is smaller and checks could be disabled for
production environments (it is useful only during development).

Put asserts at beginning of function, even before validating arguments.

The behavior of update_devfreq() is now changed because lockdep assert
will only print a warning, not return with EINVAL.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:40 +09:00
Dmitry Osipenko
a316b5ca9e PM / devfreq: Replace strncpy with strscpy
GCC produces this warning when kernel compiled using `make W=1`:

  warning: ‘strncpy’ specified bound 16 equals destination size [-Wstringop-truncation]
  772 |  strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);

The strncpy doesn't take care of NULL-termination of the destination
buffer, while the strscpy does.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:39 +09:00
Leonard Crestez
4c6abef7b4 PM / devfreq: Fix handling dev_pm_qos_remove_request result
The dev_pm_qos_remove_request function can return 1 if
"aggregated constraint value has changed" so only negative values should
be reported as errors.

Fixes: 27dbc542f6 ("PM / devfreq: Use PM QoS for sysfs min/max_freq")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-03-25 08:35:03 +09:00
Chanwoo Choi
3a1ec2e8d8 PM / devfreq: Change to DEVFREQ_GOV_UPDATE_INTERVAL event name
DEVFREQ_GOV_INTERVAL event indicates that update the interval
for polling mode of devfreq device. But, this event name doesn't
specify exactly what to do.

Change DEVFREQ_GOV_INTERVAL event name to DEVFREQ_GOV_UPDATE_INTERVAL
which specifies what to do by event name.

And modify the function name to DEVFREQ_GOV_UPDATE_INTERVAL
with 'devfreq_' prefix + verb + object as following:
- devfreq_interval_update -> devfreq_updatee_interval

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-03-25 08:35:03 +09:00
Orson Zhai
66d0e797bf Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs"
This reverts commit 4585fbcb53.

The name changing as devfreq(X) breaks some user space applications,
such as Android HAL from Unisoc and Hikey [1].
The device name will be changed unexpectly after every boot depending
on module init sequence. It will make trouble to setup some system
configuration like selinux for Android.

So we'd like to revert it back to old naming rule before any better
way being found.

[1] https://lkml.org/lkml/2018/5/8/1042

Cc: John Stultz <john.stultz@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Orson Zhai <orson.unisoc@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-02-24 11:14:29 +09:00
Chanwoo Choi
490a421bc5 PM / devfreq: Add debugfs support with devfreq_summary file
Add debugfs interface to provide debugging information of devfreq device.
It contains 'devfreq_summary' entry to show the summary of registered
devfreq devices as following and the additional debugfs file will be added.
- /sys/kernel/debug/devfreq/devfreq_summary

[Detailed description of each field of 'devfreq_summary' debugfs file]
- dev_name	: Device name of h/w
- dev		: Device name made by devfreq core
- parent_dev	: If devfreq device uses the passive governor,
		  show parent devfreq device name. Otherwise, show 'null'.
- governor	: Devfreq governor name
- polling_ms	: If devfreq device uses the simple_ondemand governor,
		  polling_ms is necessary for the period. (unit: millisecond)
- cur_freq_Hz	: Current frequency (unit: Hz)
- min_freq_Hz	: Minimum frequency (unit: Hz)
- max_freq_Hz	: Maximum frequency (unit: Hz)

[For example on Exynos5422-based Odroid-XU3 board]
$ cat /sys/kernel/debug/devfreq/devfreq_summary
dev_name                       dev        parent_dev governor        polling_ms  cur_freq_Hz  min_freq_Hz  max_freq_Hz
------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------
10c20000.memory-controller     devfreq0   null       simple_ondemand          0    165000000    165000000    825000000
soc:bus_wcore                  devfreq1   null       simple_ondemand         50    532000000     88700000    532000000
soc:bus_noc                    devfreq2   devfreq1   passive                  0    111000000     66600000    111000000
soc:bus_fsys_apb               devfreq3   devfreq1   passive                  0    222000000    111000000    222000000
soc:bus_fsys                   devfreq4   devfreq1   passive                  0    200000000     75000000    200000000
soc:bus_fsys2                  devfreq5   devfreq1   passive                  0    200000000     75000000    200000000
soc:bus_mfc                    devfreq6   devfreq1   passive                  0    333000000     83250000    333000000
soc:bus_gen                    devfreq7   devfreq1   passive                  0    266000000     88700000    266000000
soc:bus_peri                   devfreq8   devfreq1   passive                  0     66600000     66600000     66600000
soc:bus_g2d                    devfreq9   devfreq1   passive                  0    333000000     83250000    333000000
soc:bus_g2d_acp                devfreq10  devfreq1   passive                  0    266000000     66500000    266000000
soc:bus_jpeg                   devfreq11  devfreq1   passive                  0    300000000     75000000    300000000
soc:bus_jpeg_apb               devfreq12  devfreq1   passive                  0    166500000     83250000    166500000
soc:bus_disp1_fimd             devfreq13  devfreq1   passive                  0    200000000    120000000    200000000
soc:bus_disp1                  devfreq14  devfreq1   passive                  0    300000000    120000000    300000000
soc:bus_gscl_scaler            devfreq15  devfreq1   passive                  0    300000000    150000000    300000000
soc:bus_mscl                   devfreq16  devfreq1   passive                  0    666000000     84000000    666000000

[lkp: Reported the build error]
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-01-16 19:14:49 +09:00
Randy Dunlap
54cb574052 PM / devfreq: Fix multiple kernel-doc warnings
Fix kernel-doc warnings in devfreq files.
Also fix a typo.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-30 09:59:06 +09:00
Kamil Konieczny
f9002b169a PM / devfreq: Move declaration of DEVICE_ATTR_RW(min_freq)
Declaration of DEVICE_ATTR_RW(min_freq) is placed after function
max_freq_store. Move it to the correct place after min_freq_show.

Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-30 09:59:05 +09:00
Kamil Konieczny
1ebd0bc0e8 PM / devfreq: Move statistics to separate struct devfreq_stats
Count time and transitions between devfreq frequencies in separate
struct devfreq_stats for improved code readability and maintenance.

Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
[cw00.choi: Fix the merge conflict in trasn_stat_store
 and use 'devfreq->stats.*' style for consistent coding style
 and restore the clean-up code of 'devfreq->profile->*']
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-30 09:59:05 +09:00
Kamil Konieczny
14a3439681 PM / devfreq: Add clearing transitions stats
Add clearing transition table and time in states devfreq statistics
by writing 0 (zero) to trans_stat file in devfreq sysfs. An example use
is like following:

echo 0 > /sys/class/devfreq/devfreqX/trans_stat

Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
[cw00.choi: Edit return value if entering the wrong value for reset
 and use arrary3_size() to get the size of 3-dimensional array]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-30 09:59:05 +09:00
Kamil Konieczny
b76b3479da PM / devfreq: Change time stats to 64-bit
Change time stats counting to bigger type by using 64-bit jiffies.
This will make devfreq stats code look similar to cpufreq stats and
prevents overflow (for HZ = 1000 after 49.7 days).

Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-30 09:59:05 +09:00
Chanwoo Choi
2fee1a7cc6 PM / devfreq: Add new name attribute for sysfs
The commit 4585fbcb53 ("PM / devfreq: Modify the device name as devfreq(X) for
sysfs") changed the node name to devfreq(x). After this commit, it is not
possible to get the device name through /sys/class/devfreq/devfreq(X)/*.

Add new name attribute in order to get device name.

Cc: stable@vger.kernel.org
Fixes: 4585fbcb53 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-30 09:59:05 +09:00
Leonard Crestez
27dbc542f6 PM / devfreq: Use PM QoS for sysfs min/max_freq
Switch the handling of min_freq and max_freq from sysfs to use the
dev_pm_qos_request interface.

Since PM QoS handles frequencies as kHz this change reduces the
precision of min_freq and max_freq. This shouldn't introduce problems
because frequencies which are not an integer number of kHz are likely
not an integer number of Hz either.

Try to ensure compatibility by rounding min values down and rounding
max values up.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
[cw00.choi: Return -EAGAIN instead of -EINVAL if dev_pm_qos is inactive]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-09 12:19:16 +09:00
Leonard Crestez
05d7ae15cf PM / devfreq: Add PM QoS support
Register notifiers with the PM QoS framework in order to respond to
requests for DEV_PM_QOS_MIN_FREQUENCY and DEV_PM_QOS_MAX_FREQUENCY.

No notifiers are added by this patch but PM QoS constraints can be
imposed externally (for example from other devices).

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-09 12:19:16 +09:00
Leonard Crestez
42a6b25e67 PM / devfreq: Don't fail devfreq_dev_release if not in list
Right now devfreq_dev_release will print a warning and abort the rest of
the cleanup if the devfreq instance is not part of the global
devfreq_list. But this is a valid scenario, for example it can happen if
the governor can't be found or on any other init error that happens
after device_register.

Initialize devfreq->node to an empty list head in devfreq_add_device so
that list_del becomes a safe noop inside devfreq_dev_release and we can
continue the rest of the cleanup.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-09 12:19:16 +09:00
Leonard Crestez
46cecc0bf0 PM / devfreq: Introduce get_freq_range helper
Moving handling of min/max freq to a single function and call it from
update_devfreq and for printing min/max freq values in sysfs.

This changes the behavior of out-of-range min_freq/max_freq: clamping
is now done at evaluation time. This means that if an out-of-range
constraint is imposed by sysfs and it later becomes valid then it will
be enforced.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-09 12:19:16 +09:00
Leonard Crestez
e7cc792d00 PM / devfreq: Set scaling_max_freq to max on OPP notifier error
The devfreq_notifier_call functions will update scaling_min_freq and
scaling_max_freq when the OPP table is updated.

If fetching the maximum frequency fails then scaling_max_freq remains
set to zero which is confusing. Set to ULONG_MAX instead so we don't
need special handling for this case in other places.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-09 12:19:15 +09:00
Leonard Crestez
e876e710ed PM / devfreq: Fix devfreq_notifier_call returning errno
Notifier callbacks shouldn't return negative errno but one of the
NOTIFY_OK/DONE/BAD values.

The OPP core will ignore return values from notifiers but returning a
value that matches NOTIFY_STOP_MASK will stop the notification chain.

Fix by always returning NOTIFY_OK.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-12-09 12:19:15 +09:00
Marek Szyprowski
e1e047ace8 PM / devfreq: Add missing locking while setting suspend_freq
Commit 2abb0d5268 ("PM / devfreq: Lock devfreq in trans_stat_show")
revealed a missing locking while calling devfreq_update_status() function
during suspend/resume cycle.

Code analysis revealed that devfreq_set_target() function was called
without needed locks held for setting device specific suspend_freq if such
has been defined. This patch fixes that by adding the needed locking, what
fixes following kernel warning on Exynos4412-based OdroidU3 board during
system suspend:

PM: suspend entry (deep)
Filesystems sync: 0.002 seconds
Freezing user space processes ... (elapsed 0.001 seconds) done.
OOM killer disabled.
Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1385 at drivers/devfreq/devfreq.c:204 devfreq_update_status+0xc0/0x188
Modules linked in:
CPU: 2 PID: 1385 Comm: rtcwake Not tainted 5.4.0-rc6-next-20191111 #6848
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c0112588>] (unwind_backtrace) from [<c010e070>] (show_stack+0x10/0x14)
[<c010e070>] (show_stack) from [<c0afb010>] (dump_stack+0xb4/0xe0)
[<c0afb010>] (dump_stack) from [<c01272e0>] (__warn+0xf4/0x10c)
[<c01272e0>] (__warn) from [<c01273a8>] (warn_slowpath_fmt+0xb0/0xb8)
[<c01273a8>] (warn_slowpath_fmt) from [<c07d105c>] (devfreq_update_status+0xc0/0x188)
[<c07d105c>] (devfreq_update_status) from [<c07d2d70>] (devfreq_set_target+0xb0/0x15c)
[<c07d2d70>] (devfreq_set_target) from [<c07d3598>] (devfreq_suspend+0x2c/0x64)
[<c07d3598>] (devfreq_suspend) from [<c05de0b0>] (dpm_suspend+0xa4/0x57c)
[<c05de0b0>] (dpm_suspend) from [<c05def74>] (dpm_suspend_start+0x98/0xa0)
[<c05def74>] (dpm_suspend_start) from [<c0195b58>] (suspend_devices_and_enter+0xec/0xc74)
[<c0195b58>] (suspend_devices_and_enter) from [<c0196a20>] (pm_suspend+0x340/0x410)
[<c0196a20>] (pm_suspend) from [<c019480c>] (state_store+0x6c/0xc8)
[<c019480c>] (state_store) from [<c033fc50>] (kernfs_fop_write+0x10c/0x228)
[<c033fc50>] (kernfs_fop_write) from [<c02a6d3c>] (__vfs_write+0x30/0x1d0)
[<c02a6d3c>] (__vfs_write) from [<c02a9afc>] (vfs_write+0xa4/0x180)
[<c02a9afc>] (vfs_write) from [<c02a9d58>] (ksys_write+0x60/0xd8)
[<c02a9d58>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28)
Exception stack(0xed3d7fa8 to 0xed3d7ff0)
...
irq event stamp: 9667
hardirqs last  enabled at (9679): [<c0b1e7c4>] _raw_spin_unlock_irq+0x20/0x58
hardirqs last disabled at (9698): [<c0b16a20>] __schedule+0xd8/0x818
softirqs last  enabled at (9694): [<c01026fc>] __do_softirq+0x4fc/0x5fc
softirqs last disabled at (9719): [<c012fe68>] irq_exit+0x16c/0x170
---[ end trace 41ac5b57d046bdbc ]---
------------[ cut here ]------------

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-29 12:50:34 +01:00
Dmitry Osipenko
5c0f6c7959 PM / devfreq: Add new interrupt_driven flag for governors
Currently interrupt-driven governors (like NVIDIA Tegra30 ACTMON governor)
are used to set polling_ms=0 in order to avoid periodic polling of device
status by devfreq core. This means that polling interval can't be changed
by userspace for such governors.

The new governor flag allows interrupt-driven governors to convey that
devfreq core shouldn't perform polling of device status and thus generic
devfreq polling interval could be supported by these governors now.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-11-06 12:04:01 +09:00
Leonard Crestez
2abb0d5268 PM / devfreq: Lock devfreq in trans_stat_show
There is no locking in this sysfs show function so stats printing can
race with a devfreq_update_status called as part of freq switching or
with initialization.

Also add an assert in devfreq_update_status to make it clear that lock
must be held by caller.

Fixes: 39688ce6fa ("PM / devfreq: account suspend/resume for stats")
Cc: stable@vger.kernel.org
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-11-06 12:04:00 +09:00
Leonard Crestez
d68adc8f85 PM / devfreq: Check NULL governor in available_governors_show
The governor is initialized after sysfs attributes become visible so in
theory the governor field can be NULL here.

Fixes: bcf23c79c4 ("PM / devfreq: Fix available_governor sysfs")
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-11-06 12:03:59 +09:00
Matthias Kaehlcke
df4d7b1451 PM / devfreq: Make log message more explicit when devfreq device already exists
Before creating a new devfreq device devfreq_add_device() checks
if there is already a devfreq dev associated with the requesting
device (parent). If that's the case the function rejects to create
another devfreq dev for that parent and logs an error. The error
message is very unspecific, make it a bit more explicit.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-11-06 12:03:59 +09:00
Krzysztof Kozlowski
e2fc1677ee PM / devfreq: Correct devm_devfreq_remove_device() documentation
Correct the documentation for devm_devfreq_remove_device() argument.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2019-08-25 12:45:34 +09:00
Ezequiel Garcia
7544fd7f38 PM / devfreq: Fix kernel oops on governor module load
A bit unexpectedly (but still documented), request_module may
return a positive value, in case of a modprobe error.
This is currently causing issues in the devfreq framework.

When a request_module exits with a positive value, we currently
return that via ERR_PTR. However, because the value is positive,
it's not a ERR_VALUE proper, and is therefore treated as a
valid struct devfreq_governor pointer, leading to a kernel oops.

Fix this by returning -EINVAL if request_module returns a positive
value.

Fixes: b53b012805 ("PM / devfreq: Fix static checker warning in try_then_request_governor")
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2019-08-24 20:11:12 +09:00
Gaël PORTAY
2c09083293 PM / devfreq: Fix spelling typo
Add missing 'r' in "monitoing".

Signed-off-by: Gaël PORTAY <gael.portay@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2019-08-24 20:11:12 +09:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  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

  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 #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Lukasz Luba
cf451adfa3 PM / devfreq: add tracing for scheduling work
This patch add basic tracing of the devfreq workqueue and delayed work.
It aims to capture changes of the polling intervals and device state.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2019-04-16 09:29:18 +09:00
Enric Balletbo i Serra
b53b012805 PM / devfreq: Fix static checker warning in try_then_request_governor
The patch 23c7b54ca1: "PM / devfreq: Fix devfreq_add_device() when
drivers are built as modules." leads to the following static checker
warning:

    drivers/devfreq/devfreq.c:1043 governor_store()
    warn: 'governor' can also be NULL

The reason is that the try_then_request_governor() function returns both
error pointers and NULL. It should just return error pointers, so fix
this by returning a ERR_PTR to the error intead of returning NULL.

Fixes: 23c7b54ca1 ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2019-04-16 09:29:18 +09:00
Saravana Kannan
bc658bef97 PM / devfreq: Restart previous governor if new governor fails to start
If the new governor fails to start, switch back to old governor so that the
devfreq state is not left in some weird limbo.

[Myungjoo: assume fatal on revert failure and set df->governor to NULL]
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2019-04-16 09:29:18 +09:00
MyungJoo Ham
6d690f7793 PM / devfreq: consistent indentation
Following up with complaints on inconsistent indentation from
Yangtao Li, this fixes indentation inconsistency.

In principle, this tries to put arguments aligned to the left
including the first argument except for the case where
the first argument is on the far-right side.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Yangtao Li <tiny.windzz@gmail.com>
2019-04-16 09:29:18 +09:00
Yangtao Li
25846fa1ce PM / devfreq: fix missing check of return value in devfreq_add_device()
devm_kzalloc() could fail, so insert a check of its return value. And
if it fails, returns -ENOMEM.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2019-04-16 09:29:18 +09:00
Yangtao Li
a9487917ba PM / devfreq: fix mem leak in devfreq_add_device()
'devfreq' is malloced in devfreq_add_device() and should be freed in
the error handling cases, otherwise it will cause memory leak.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2019-04-16 09:29:18 +09:00
Lukasz Luba
5903195605 PM / devfreq: add devfreq_suspend/resume() functions
This patch adds implementation for global suspend/resume for
devfreq framework. System suspend will next use these functions.

Suggested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Suggested-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2018-12-11 11:40:13 +09:00
Lukasz Luba
83f8ca45af PM / devfreq: add support for suspend/resume of a devfreq device
The patch prepares devfreq device for handling suspend/resume
functionality. The new fields will store needed information during this
process. Devfreq framework handles opp-suspend DT entry and there is no
need of modyfications in the drivers code. It uses atomic variables to
make sure no race condition affects the process.

Suggested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Suggested-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2018-12-11 11:09:47 +09:00
Lukasz Luba
633141721b PM / devfreq: refactor set_target frequency function
The refactoring is needed for the new client in devfreq: suspend.
To avoid code duplication, move it to the new local function
devfreq_set_target.

Suggested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Suggested-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2018-12-11 11:09:44 +09:00
zhong jiang
8188b154f9 PM / devfreq: remove redundant null pointer check before kfree
kfree has taken the null pointer into account. hence it is safe
to remove the redundant null pointer check before kfree.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2018-10-02 10:16:41 +09:00
Vincent Donnefort
2f061fd0c2 PM / devfreq: stopping the governor before device_unregister()
device_release() is freeing the resources before calling the device
specific release callback which is, in the case of devfreq, stopping
the governor.

It is a problem as some governors are using the device resources. e.g.
simpleondemand which is using the devfreq deferrable monitoring work. If it
is not stopped before the resources are freed, it might lead to a use after
free.

Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Reviewed-by: John Einar Reitan <john.reitan@arm.com>
[cw00.choi: Fix merge conflict]
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2018-10-02 10:16:41 +09:00