The cooling devices have their cooling device set_cur_state
read-writable all the time in the sysfs directory, thus allowing the
userspace to act on it.
The thermal framework is wrongly used by userspace as a power capping
framework by acting on the cooling device opaque state. This one then
competes with the in-kernel governor decision.
We have seen in out-of-tree kernels, a big number of devices which are
abusely declaring themselves as cooling device just to act on their
power.
The role of the thermal framework is to protect the junction
temperature of the silicon. Letting the userspace to play with a
cooling device is invalid and potentially dangerous.
The powercap framework is the right framework to do power capping and
moreover it deals with the aggregation via the dev pm qos.
As the userspace governor is marked deprecated and about to be
removed, there is no point to keep this file writable also in the
future.
Emit a warning and deprecate the interface.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20211019163506.2831454-2-daniel.lezcano@linaro.org
There is a possible chance that some cooling device stats buffer
allocation fails due to very high cooling device max state value.
Later cooling device update sysfs can try to access stats data
for the same cooling device. It will lead to NULL pointer
dereference issue.
Add a NULL pointer check before accessing thermal cooling device
stats data. It fixes the following bug
[ 26.812833] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
[ 27.122960] Call trace:
[ 27.122963] do_raw_spin_lock+0x18/0xe8
[ 27.122966] _raw_spin_lock+0x24/0x30
[ 27.128157] thermal_cooling_device_stats_update+0x24/0x98
[ 27.128162] cur_state_store+0x88/0xb8
[ 27.128166] dev_attr_store+0x40/0x58
[ 27.128169] sysfs_kf_write+0x50/0x68
[ 27.133358] kernfs_fop_write+0x12c/0x1c8
[ 27.133362] __vfs_write+0x54/0x160
[ 27.152297] vfs_write+0xcc/0x188
[ 27.157132] ksys_write+0x78/0x108
[ 27.162050] ksys_write+0xf8/0x108
[ 27.166968] __arm_smccc_hvc+0x158/0x4b0
[ 27.166973] __arm_smccc_hvc+0x9c/0x4b0
[ 27.186005] el0_svc+0x8/0xc
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1607367181-24589-1-git-send-email-manafm@codeaurora.org
The code was reorganized in 2012 with the commit 0c01ebbfd3.
The main change is a loop on the trip points array and a unconditional
call to the throttle() ops of the governors for each of them even if
the trip temperature is not reached yet.
With this change, the 'forced_passive' is no longer checked in the
thermal_zone_device_update() function but in the step wise governor's
throttle() callback.
As the force_passive does no belong to the trip point array, the
thermal_zone_device_update() can not compare with the specified
passive temperature, thus does not detect the passive limit has been
crossed. Consequently, throttle() is never called and the
'forced_passive' branch is unreached.
In addition, the default processor cooling device is not automatically
bound to the thermal zone if there is not passive trip point, thus the
'forced_passive' can not operate.
If there is an active trip point, then the throttle function will be
called to mitigate at this temperature and the 'forced_passive' will
override the mitigation of the active trip point in this case but with
the default cooling device bound to the thermal zone, so usually a
fan, and that is not a passive cooling effect.
Given the regression exists since more than 8 years, nobody complained
and at the best of my knowledge there is no bug open in
https://bugzilla.kernel.org, it is reasonable to say it is unused.
Remove the 'forced_passive' related code.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
Link: https://lore.kernel.org/r/20201214233811.485669-1-daniel.lezcano@linaro.org
The only usage of these structs is to assign their address to the
thermal_zone_attribute_groups array, which consists of pointers to
const, so make them const to allow the compiler to put them in read-only
memory.
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201128234342.36684-1-rikard.falkeborn@gmail.com
The generic netlink protocol is implemented but the different
notification functions are not yet connected to the core code.
These changes add the notification calls in the different
corresponding places.
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20200706105538.2159-4-daniel.lezcano@linaro.org
Use thermal_zone_device_{en|dis}able() and thermal_zone_device_is_enabled().
Consequently, all set_mode() implementations in drivers:
- can stop modifying tzd's "mode" member,
- shall stop taking tzd's lock, as it is taken in the helpers
- shall stop calling thermal_zone_device_update() as it is called in the
helpers
- can assume they are called when the mode truly changes, so checks to
verify that can be dropped
Not providing set_mode() by a driver no longer prevents the core from
being able to set tzd's mode, so the relevant check in mode_store() is
removed.
Other comments:
- acpi/thermal.c: tz->thermal_zone->mode will be updated only after we
return from set_mode(), so use function parameter in thermal_set_mode()
instead, no need to call acpi_thermal_check() in set_mode()
- thermal/imx_thermal.c: regmap writes and mode assignment are done in
thermal_zone_device_{en|dis}able() and set_mode() callback
- thermal/intel/intel_quark_dts_thermal.c: soc_dts_{en|dis}able() are a
part of set_mode() callback, so they don't need to modify tzd->mode, and
don't need to fall back to the opposite mode if unsuccessful, as the return
value will be propagated to thermal_zone_device_{en|dis}able() and
ultimately tzd's member will not be changed in thermal_zone_device_set_mode().
- thermal/of-thermal.c: no need to set zone->mode to DISABLED in
of_parse_thermal_zones() as a tzd is kzalloc'ed so mode is DISABLED anyway
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
[for acerhdf]
Acked-by: Peter Kaestle <peter@piie.net>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-8-andrzej.p@collabora.com
get_mode() is now redundant, as the state is stored in struct
thermal_zone_device.
Consequently the "mode" attribute in sysfs can always be visible, because
it is always possible to get the mode from struct tzd.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
[for acerhdf]
Acked-by: Peter Kaestle <peter@piie.net>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-6-andrzej.p@collabora.com
Sysfs interface to update cooling device cur_state does not
currently holding cooling device lock sometimes leading to
stale values in cur_state if getting updated simultanelously
from user space and thermal framework. Adding the proper locking
code fixes this issue.
Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Use the DEVICE_ATTR_{RO|RW|WO}() variants instead of DEVICE_ATTR().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
The naming isn't consistent across all sysfs callbacks in the thermal
core, some have a short name like type_show() and others have long names
like thermal_cooling_device_weight_show(). This patch tries to make it
consistent by shortening the name of sysfs callbacks.
Some of the sysfs files are named similarly for both thermal zone and
cooling device (like: type) and to avoid name clash between their
show/store routines, the cooling device specific sysfs callbacks are
prefixed with "cdev_".
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This extends the sysfs interface for thermal cooling devices and exposes
some pretty useful statistics. These statistics have proven to be quite
useful specially while doing benchmarks related to the task scheduler,
where we want to make sure that nothing has disrupted the test,
specially the cooling device which may have put constraints on the CPUs.
The information exposed here tells us to what extent the CPUs were
constrained by the thermal framework.
The write-only "reset" file is used to reset the statistics.
The read-only "time_in_state_ms" file shows the time (in msec) spent by the
device in the respective cooling states, and it prints one line per
cooling state.
The read-only "total_trans" file shows single positive integer value
showing the total number of cooling state transitions the device has
gone through since the time the cooling device is registered or the time
when statistics were reset last.
The read-only "trans_table" file shows a two dimensional matrix, where
an entry <i,j> (row i, column j) represents the number of transitions
from State_i to State_j.
This is how the directory structure looks like for a single cooling
device:
$ ls -R /sys/class/thermal/cooling_device0/
/sys/class/thermal/cooling_device0/:
cur_state max_state power stats subsystem type uevent
/sys/class/thermal/cooling_device0/power:
autosuspend_delay_ms runtime_active_time runtime_suspended_time
control runtime_status
/sys/class/thermal/cooling_device0/stats:
reset time_in_state_ms total_trans trans_table
This is tested on ARM 64-bit Hisilicon hikey620 board running Ubuntu and
ARM 64-bit Hisilicon hikey960 board running Android.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
In order to easily free resources allocated by
'thermal_zone_create_device_groups()' we need 2 new helper functions.
The first one undoes 'thermal_zone_create_device_groups()'.
The 2nd one undoes 'create_trip_attrs()', which is a function called by
'thermal_zone_create_device_groups()'.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Remove the following warning:
In file included from drivers/thermal/thermal_sysfs.c:19:0:
include/linux/device.h:575:26: warning: ‘dev_attr_emul_temp’ defined but not used [-Wunused-variable]
struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
^
drivers/thermal/thermal_sysfs.c:395:8: note: in expansion of macro ‘DEVICE_ATTR’
when emul temp is disabled at Kconfig.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This is a code reorganization, simply to concentrate
the sysfs handling functions in thermal_sysfs.c.
This patch moves the cooling device handling functions.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
This is a code reorganization, simply to concentrate
the code handling sysfs in a specific file: thermal_sysfs.c.
Right now, moving only the sysfs entries of thermal_zone_device.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
