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>
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>
Commit ab8f58ad72 ("PM / devfreq: Set min/max_freq when adding the
devfreq device") initializes df->min/max_freq with the min/max OPP when
the device is added. Later commit f1d981eaec ("PM / devfreq: Use the
available min/max frequency") adds df->scaling_min/max_freq and the
following to the frequency adjustment code:
max_freq = MIN(devfreq->scaling_max_freq, devfreq->max_freq);
With the current handling of min/max_freq this is incorrect:
Even though df->max_freq is now initialized to a value != 0 user space
can still set it to 0, in this case max_freq would be 0 instead of
df->scaling_max_freq as intended. In consequence the frequency adjustment
is not performed:
if (max_freq && freq > max_freq) {
freq = max_freq;
To fix this set df->min/max freq to the min/max OPP in max/max_freq_store,
when the user passes a value of 0. This also prevents df->max_freq from
being set below the min OPP when df->min_freq is 0, and similar for
min_freq. Since it is now guaranteed that df->min/max_freq can't be 0 the
checks for this case can be removed.
Fixes: f1d981eaec ("PM / devfreq: Use the available min/max frequency")
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
When the devfreq driver and the governor driver are built as modules,
the call to devfreq_add_device() or governor_store() fails because the
governor driver is not loaded at the time the devfreq driver loads. The
devfreq driver has a build dependency on the governor but also should
have a runtime dependency. We need to make sure that the governor driver
is loaded before the devfreq driver.
This patch fixes this bug by adding a try_then_request_governor()
function. First tries to find the governor, and then, if it is not found,
it requests the module and tries again.
Fixes: 1b5c1be2c8 (PM / devfreq: map devfreq drivers to governor using name)
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>
Commit ab8f58ad72 ("PM / devfreq: Set min/max_freq when adding
the devfreq device") introduced the initialization of the user
limits min/max_freq from the lowest/highest available OPPs. Later
commit f1d981eaec ("PM / devfreq: Use the available min/max
frequency") added scaling_min/max_freq, which actually represent
the frequencies of the lowest/highest available OPP. scaling_min/
max_freq are initialized with the values from min/max_freq, which
is totally correct in the context, but a bit awkward to read.
Swap the initialization and assign scaling_min/max_freq with the
OPP freqs and then the user limts min/max_freq with scaling_min/
max_freq.
Needless to say that this change is a NOP, intended to improve
readability.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Never directly free @dev after calling device_register() or
device_unregister(), even if device_register() returned an error.
Always use put_device() to give up the reference initialized.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
df->governor is being dereferenced before it is null checked,
hence there is a potential null pointer dereference.
Notice that df->governor is being null checked at line 1004:
if (df->governor) {, which implies it might be null.
Fix this by null checking df->governor before dereferencing it.
Addresses-Coverity-ID: 1401988 ("Dereference before null check")
Fixes: bcf23c79c4 ("PM / devfreq: Fix available_governor sysfs")
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Propagate the error of devfreq_add_device() in devm_devfreq_add_device()
rather than statically returning ENOMEM. This makes it slightly faster
to pinpoint the cause of a returned error.
Fixes: 8cd84092d3 ("PM / devfreq: Add resource-managed function for devfreq device")
Cc: stable@vger.kernel.org
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
The freq_table array of each devfreq device is always not NULL.
In result, it is unneeded to check whether profile->freq_table
is NULL or not.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
The commit a76caf55e5 ("thermal: Add devfreq cooling") allows
the devfreq device to use the cooling device. When the cooling down
are required, the devfreq_cooling.c disables the OPP entry with
the dev_pm_opp_disable(). In result, 'available_frequencies'[1]
sysfs node never came to show the all available frequencies.
[1] /sys/class/devfreq/.../available_frequencies
So, this patch uses the 'freq_table' in the 'struct devfreq_dev_profile'
in order to show the all available frequencies.
- If 'freq_table' is NULL, devfreq core initializes them by using OPP values.
- If 'freq_table' is initialized, devfreq core just uses the 'freq_table'.
And this patch adds some comment about the sort way of 'freq_table'.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
This patch changes the return type of devfreq_set_freq_table()
from 'void' to 'int' in order to check whether it fails or not.
And This patch just removes the 'devfreq' prefix and the description
of function. Because the helper functions are only used by the devfreq.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
The commit a76caf55e5 ("thermal: Add devfreq cooling") is able
to disable OPP as a cooling device. In result, both update_devfreq()
and {min|max}_freq_show() have to consider the 'opp->available'
status of each OPP.
So, this patch adds the 'scaling_{min|max}_freq' to struct devfreq
in order to indicate the available mininum and maximum frequency
by adjusting OPP interface such as dev_pm_opp_{disable|enable}().
The 'scaling_{min|max}_freq' are used for on both update_devfreq()
and {min|max}_freq_show().
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
This reverts commit 3104fa3081.
The {min|max}_freq_show() show the stored value of the struct devfreq.
But, if the drivers/thermal/devfreq_cooling.c disables the specific
frequency value, {min|max}_freq_show() have to check this situation
before showing the stored value. So, this patch revert the macro
in order to add the additional codes.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Prior to that, the min/max_freq of the devfreq device are always zero
before the user changes the min/max_freq through sysfs entries.
It might make the confusion for the min/max_freq.
This patch initializes the available min/max_freq by using the OPP
during adding the devfreq device.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
When the devfreq_add_device fails to register deivce, the memory
leak of devfreq instance happen. So, this patch fix the memory
leak issue. Before freeing the devfreq instance checks whether
devfreq instance is NULL or not because the device_unregister()
frees the devfreq instance when jumping to the 'err_init'.
It is to prevent the duplicate the kfee(devfreq).
Cc: stable@vger.kernel.org
Fixes: ac4b281176 ("PM / devfreq: fix duplicated kfree on devfreq pointer")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
* pm-devfreq:
PM / devfreq: Modify the device name as devfreq(X) for sysfs
PM / devfreq: Simplify the sysfs name of devfreq-event device
PM / devfreq: Remove unnecessary separate _remove_devfreq()
PM / devfreq: Fix wrong trans_stat of passive devfreq device
PM / devfreq: Fix available_governor sysfs
PM / devfreq: exynos-ppmu: Show the registred device for ppmu device
PM / devfreq: Fix the wrong description for userspace governor
PM / devfreq: Fix the checkpatch warnings
PM / devfreq: exynos-bus: Print the real clock rate of bus
PM / devfreq: exynos-ppmu: Use the regmap interface to handle the registers
PM / devfreq: exynos-bus: Add the detailed correlation for Exynos5433
PM / devfreq: Don't delete sysfs group twice
This patch modifies the device name as devfreq(X) for sysfs by using the 'devfreq'
prefix word instead of separate device name. On user-space aspect, user would
find the some devfreq drvier with 'devfreq(X)' pattern. So, this patch modify the
device name as following:
- /sys/class/devfreq/[non-standard device name] -> /sys/class/devfreq/devfreq(X)
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
The _remove_devfreq() releases the all resources of the devfreq
device. This function is only called in the devfreq_dev_release().
For that reason, the devfreq core doesn't need to leave the
_remove_devfreq() separately. This patch releases the all
resources in the devfreq_dev_release() and then removes the
_remove_devfreq().
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Until now, the trans_stat information of passive devfreq is not updated.
This patch updates the trans_stat information after setting the target
frequency of passive devfreq device.
Fixes: 996133119f ("PM / devfreq: Add new passive governor")
Cc: stable@vger.kernel.org
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
