stable inclusion
from stable-5.10.37
commit 0681c62d1ea2eba43aa8efb03708f7c3334fd863
bugzilla: 51868
CVE: NA

--------------------------------

[ Upstream commit 62453f1b ]

Use the more accurate returned new_freq as resume_freq.
It's the same as how devfreq->previous_freq was updated.

Fixes: 83f8ca45 ("PM / devfreq: add support for suspend/resume of a devfreq device")
Signed-off-by: NDong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

stable inclusion
from stable-5.10.37
commit 2f2d444ac4964ddd489090b16cc8ab2b06cbca04
bugzilla: 51868
CVE: NA

--------------------------------

commit 8b50a799 upstream.

The devfreq->lock is held for time of setup. Release the lock in the
error path, before jumping to the end of the function.

Change the goto destination which frees the allocated memory.

Cc: v5.9+ <stable@vger.kernel.org> # v5.9+
Fixes: 4dc3bab8 ("PM / devfreq: Add support delayed timer for polling mode")
Signed-off-by: NLukasz Luba <lukasz.luba@arm.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.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: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NChanwoo 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: NKrzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: NLukasz Luba <lukasz.luba@arm.com>
Signed-off-by: NLeonard 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: NChanwoo Choi <cw00.choi@samsung.com>

The commit 4dc3bab8 ("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: 4dc3bab8 ("PM / devfreq: Add support delayed timer for polling mode")
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

Fix the wrong grammar at the end of code line by using semicolon.

Cc: stable vger.kernel.org
Fixes: 490a421b ("PM / devfreq: Add debugfs support with devfreq_summary file")
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

The commit 66d0e797 ("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 66d0e797,
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: 66d0e797 ("Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs"")
Signed-off-by: NChanwoo 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: NChanwoo 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: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NLukasz Luba <lukasz.luba@arm.com>
Signed-off-by: NChanwoo 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: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NChanwoo 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: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NChanwoo 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: 27dbc542 ("PM / devfreq: Use PM QoS for sysfs min/max_freq")
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: NChanwoo 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: NLukasz Luba <lukasz.luba@arm.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

This reverts commit 4585fbcb.

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: NOrson Zhai <orson.unisoc@gmail.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

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: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

Fix kernel-doc warnings in devfreq files.
Also fix a typo.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NChanwoo 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: NKamil Konieczny <k.konieczny@samsung.com>
Signed-off-by: NChanwoo 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: NKamil Konieczny <k.konieczny@samsung.com>
Reviewed-by: NMatthias 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: NChanwoo 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: NKamil 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: NChanwoo 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: NKamil Konieczny <k.konieczny@samsung.com>
Acked-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

The commit 4585fbcb ("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: 4585fbcb ("PM / devfreq: Modify the device name as devfreq(X) for sysfs")
Signed-off-by: NChanwoo 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: NLeonard Crestez <leonard.crestez@nxp.com>
Acked-by: NChanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Tested-by: NMatthias Kaehlcke <mka@chromium.org>
[cw00.choi: Return -EAGAIN instead of -EINVAL if dev_pm_qos is inactive]
Signed-off-by: NChanwoo 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: NLeonard Crestez <leonard.crestez@nxp.com>
Acked-by: NChanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Tested-by: NMatthias Kaehlcke <mka@chromium.org>
Signed-off-by: NChanwoo 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: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo 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: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo 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: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo 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: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

Commit 2abb0d52 ("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: NMarek Szyprowski <m.szyprowski@samsung.com>
Acked-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NRafael 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: NDmitry Osipenko <digetx@gmail.com>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo 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: 39688ce6 ("PM / devfreq: account suspend/resume for stats")
Cc: stable@vger.kernel.org
Signed-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo 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: bcf23c79 ("PM / devfreq: Fix available_governor sysfs")
Signed-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo 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: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

Correct the documentation for devm_devfreq_remove_device() argument.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungJoo 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: b53b0128 ("PM / devfreq: Fix static checker warning in try_then_request_governor")
Signed-off-by: NEzequiel Garcia <ezequiel@collabora.com>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>

Add missing 'r' in "monitoing".
Signed-off-by: NGaël PORTAY <gael.portay@collabora.com>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungJoo 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: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NEnrico Weigelt <info@metux.net>
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.deSigned-off-by: NGreg 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: NLukasz Luba <l.luba@partner.samsung.com>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>

The patch 23c7b54c: "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: 23c7b54c ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.")
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NEnric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungJoo 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: NSibi Sankar <sibis@codeaurora.org>
Signed-off-by: NSaravana Kannan <skannan@codeaurora.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NMyungJoo 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: NMyungJoo Ham <myungjoo.ham@samsung.com>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NYangtao Li <tiny.windzz@gmail.com>