linux-toradex.git/drivers/cpufreq/cpufreq_userspace.c, branch v5.0

cpufreq: governor: Get rid of governor events

2016-06-02T21:24:15+00:00

The design of the cpufreq governor API is not very straightforward,
as struct cpufreq_governor provides only one callback to be invoked
from different code paths for different purposes.  The purpose it is
invoked for is determined by its second "event" argument, causing it
to act as a "callback multiplexer" of sorts.

Unfortunately, that leads to extra complexity in governors, some of
which implement the ->governor() callback as a switch statement
that simply checks the event argument and invokes a separate function
to handle that specific event.

That extra complexity can be eliminated by replacing the all-purpose
->governor() callback with a family of callbacks to carry out specific
governor operations: initialization and exit, start and stop and policy
limits updates.  That also turns out to reduce the code size too, so
do it.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Viresh Kumar

cpufreq: Fix GOV_LIMITS handling for the userspace governor

2016-05-04T23:30:38+00:00

Currently, the userspace governor only updates frequency on GOV_LIMITS
if policy->cur falls outside policy->{min/max}. However, it is also
necessary to update current frequency on GOV_LIMITS to match the user
requested value if it can be achieved within the new policy->{max/min}.

This was previously the behaviour in the governor until commit d1922f0
("cpufreq: Simplify userspace governor") which incorrectly assumed that
policy->cur == user requested frequency via scaling_setspeed. This won't
be true if the user requested frequency falls outside policy->{min/max}.
Ex: a temporary thermal cap throttled the user requested frequency.

Fix this by storing the user requested frequency in a seperate variable.
The governor will then try to achieve this request on every GOV_LIMITS
change.

Fixes: d1922f02562f (cpufreq: Simplify userspace governor)
Signed-off-by: Sai Gurrappadi 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Clean up default and fallback governor setup

2016-02-05T01:37:42+00:00

The preprocessor magic used for setting the default cpufreq governor
(and for using the performance governor as a fallback one for that
matter) is really nasty, so replace it with __weak functions and
overrides.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Saravana Kannan 
Acked-by: Viresh Kumar

cpufreq / governor: Remove fossil comment

2013-10-17T21:00:20+00:00

cpufreq_set_policy() has been changed to origin __cpufreq_set_policy()
and policy->lock has been converted to rewrite lock by commit 5a01f2.
So remove the comment.

Acked-by: Viresh Kumar 
Signed-off-by: Lan Tianyu 
Signed-off-by: Rafael J. Wysocki

cpufreq: Fix minor formatting issues

2013-06-20T23:06:34+00:00

There were a few noticeable formatting issues in core cpufreq code.
This cleans them up to make code look better.  The changes include:
 - Whitespace cleanup.
 - Rearrangements of code.
 - Multiline comments fixes.
 - Formatting changes to fit 80 columns.

Copyright information in cpufreq.c is also updated to include my name
for 2013.

[rjw: Changelog]
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Simplify userspace governor

2013-06-19T00:01:07+00:00

Userspace governor has got more code than what it needs for its
functioning, so simplify it.

Portions of code removed are:
 - Extra header files which aren't required anymore (rearrange them
   as well).
 - cpu_{max|min|cur|set}_freq, as they are always the same as
   policy->{max|min|cur}.
 - userspace_cpufreq_notifier_block as we don't need to set
   cpu_cur_freq anymore.
 - cpus_using_userspace_governor as it was for the notifier code.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Don't check cpu_online(policy->cpu)

2013-02-09T00:18:34+00:00

policy->cpu or cpus in policy->cpus can't be offline anymore. And so we don't
need to check if they are online or not.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Improve debug prints

2012-11-14T23:33:06+00:00

With debug options on, it is difficult to locate cpufreq core's debug prints.
Fix this by prefixing debug prints with KBUILD_MODNAME.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

[CPUFREQ] cpufreq:userspace: fix cpu_cur_freq updation

2012-01-06T15:10:53+00:00

CPU frequency is guranteed to be changed on notifier callback with
CPUFREQ_POSTCHANGE. Notifier callback with CPUFREQ_PRECHANGE does
not gurantee a change in frequency; after it, if cpufreq driver is
unable to change CPU to new frequency. This results in wrong
information being fed to user (if setting CPU frequency fails)
upon doing like,

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

Hence in userspace governer update cpu_cur_freq only if notifier
has been called with POSTCHANGE.

Signed-off-by: Afzal Mohammed 
Signed-off-by: Dave Jones

[CPUFREQ] use dynamic debug instead of custom infrastructure

2011-05-04T15:50:57+00:00

With dynamic debug having gained the capability to report debug messages
also during the boot process, it offers a far superior interface for
debug messages than the custom cpufreq infrastructure. As a first step,
remove the old cpufreq_debug_printk() function and replace it with a call
to the generic pr_debug() function.

How can dynamic debug be used on cpufreq? You need a kernel which has
CONFIG_DYNAMIC_DEBUG enabled.

To enabled debugging during runtime, mount debugfs and

$ echo -n 'module cpufreq +p' > /sys/kernel/debug/dynamic_debug/control

for debugging the complete "cpufreq" module. To achieve the same goal during
boot, append

	ddebug_query="module cpufreq +p"

as a boot parameter to the kernel of your choice.

For more detailled instructions, please see
Documentation/dynamic-debug-howto.txt

Signed-off-by: Dominik Brodowski 
Signed-off-by: Dave Jones