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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
The patch 23c7b54ca1cd: "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>
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>
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>
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>
'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>
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>
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>
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>
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>
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>
Chanwoo Choi