Most of the drivers do following in their ->target_index() routines:
struct cpufreq_freqs freqs;
freqs.old = old freq...
freqs.new = new freq...
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
/* Change rate here */
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
This is replicated over all cpufreq drivers today and there doesn't exists a
good enough reason why this shouldn't be moved to cpufreq core instead.
There are few special cases though, like exynos5440, which doesn't do everything
on the call to ->target_index() routine and call some kind of bottom halves for
doing this work, work/tasklet/etc..
They may continue doing notification from their own code as flag:
CPUFREQ_ASYNC_NOTIFICATION is already set for them.
All drivers are also modified in this patch to avoid breaking 'git bisect', as
double notification would happen otherwise.
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently, the prototype of cpufreq_drivers target routines is:
int target(struct cpufreq_policy *policy, unsigned int target_freq,
unsigned int relation);
And most of the drivers call cpufreq_frequency_table_target() to get a valid
index of their frequency table which is closest to the target_freq. And they
don't use target_freq and relation after that.
So, it makes sense to just do this work in cpufreq core before calling
cpufreq_frequency_table_target() and simply pass index instead. But this can be
done only with drivers which expose their frequency table with cpufreq core. For
others we need to stick with the old prototype of target() until those drivers
are converted to expose frequency tables.
This patch implements the new light weight prototype for target_index() routine.
It looks like this:
int target_index(struct cpufreq_policy *policy, unsigned int index);
CPUFreq core will call cpufreq_frequency_table_target() before calling this
routine and pass index to it. Because CPUFreq core now requires to call routines
present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time.
This also marks target() interface as deprecated. So, that new drivers avoid
using it. And Documentation is updated accordingly.
It also converts existing .target() to newly defined light weight
.target_index() routine for many driver.
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King <linux@arm.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Many common initializations of struct policy are moved to core now and hence
this driver doesn't need to do it. This patch removes such code.
Most recent of those changes is to call ->get() in the core after calling
->init().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Most of the CPUFreq drivers do similar things in .exit() and .verify() routines
and .attr. So its better if we have generic routines for them which can be used
by cpufreq drivers then.
This patch uses these generic routines in the e_powersaver driver.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Lets use cpufreq_table_validate_and_show() instead of calling
cpufreq_frequency_table_cpuinfo() and cpufreq_frequency_table_get_attr().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We don't need to set .owner = THIS_MODULE any more in cpufreq drivers
as this field isn't used any more by the cpufreq core.
This patch removes it and updates all dependent drivers accordingly.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Chapter 14 of Documentation/CodingStyle says:
The preferred form for passing a size of a struct is the following:
p = kmalloc(sizeof(*p), ...);
The alternative form where struct name is spelled out hurts
readability and introduces an opportunity for a bug when the pointer
variable type is changed but the corresponding sizeof that is passed
to a memory allocator is not.
This wasn't followed consistently in drivers/cpufreq, let's make it
more consistent by always following this rule.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In case we have started PRECHANGE notifier and found an error, we
must call POSTCHANGE notifier with freqs.new = freqs.old.
This driver does take care of it, but the POSTCHANGE is called with
freqs.new on errors too, which is incorrect, so fix it.
[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The "index" field of struct cpufreq_frequency_table was never an
index and isn't used at all by the cpufreq core. It only is useful
for cpufreq drivers for their internal purposes.
Many people nowadays blindly set it in ascending order with the
assumption that the core will use it, which is a mistake.
Rename it to "driver_data" as that's what its purpose is. All of its
users are updated accordingly.
[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
policy->cpus contains all online cpus that have single shared clock line. And
their frequencies are always updated together.
Many SMP system's cpufreq drivers take care of this in individual drivers but
the best place for this code is in cpufreq core.
This patch modifies cpufreq_notify_transition() to notify frequency change for
all cpus in policy->cpus and hence updates all users of this API.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This marks all the x86 cpuinfo tables to the CPU specific device drivers,
to allow auto loading by udev. This should simplify the distribution
startup scripts for this greatly.
I didn't add MODULE_DEVICE_IDs to the centrino and p4-clockmod drivers,
because those probably shouldn't be auto loaded and the acpi driver
be used instead (not fully sure on that, would appreciate feedback)
The old nforce drivers autoload based on the PCI ID.
ACPI cpufreq is autoloaded in another patch.
v3: Autoload gx based on PCI IDs only. Remove cpu check (Dave Jones)
v4: Use newly introduce HW_PSTATE feature for powernow-k8 loading
Cc: Dave Jones <davej@redhat.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add new module option "set_max_voltage".
One of the lessons learned from Adaptive Powersaver is that voltage values
returned by processor are for worst case scenario. But required voltage
is changing with CPU temperature. And even processors produced in the same
batch can have different minimum voltage necessary for stable work at
specified frequency.
On Elonex Webbook, once system starts, temperature never drops below
48 deg. C. Loading module after systems start allows user to lower CPU
voltage and still have stable system.
Sadly C7 doesn't allow code to set frequency or voltage from outside limits.
If you ask it to set voltage lower then minimum it will ignore you. Thats
why it isn't possible to change minimum voltage for minimum frequency too.
Changing maximum voltage on Elonex Webbook leads to very good results. Looks
like VIA C7 1.6GHz 1084mV can safetly run at 892mV. This means 83% of
orginal value. If same percentage applies to power generated it means 12.5W
in the place of 15W. Not much, but it is better then nothing.
Only C7-M makes it possible.
If voltage is too low by 16mV or more you will experience kernel panic.
If voltage is too low by 32mV or more you will experience system freeze.
Signed-off-by: Rafał Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
Call ACPI function to get BIOS limit for CPU frequency.
Fail if processor would like to run at higher frequency.
Allow user to ignore BIOS limit.
eps: Detected VIA Model D C7-M
eps: Current voltage = 1084mV
eps: Current multiplier = 16
eps: Highest voltage = 1084mV
eps: Highest multiplier = 16
eps: Lowest voltage = 844mV
eps: Lowest multiplier = 4
eps: ACPI limit 1.60GHz
Signed-off-by: Rafał Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
Some systems are using 1,2Ghz@844mV processors running at 600MHz@796mV.
Try to detect such systems and don't touch anything on it. If CPU doesn't have
P-States in BIOS it should run at maximum frequency.
Allow user to bypass checks by means of two new options.
Don't set frequency to maximum on module unloading to avoid bada boom.
It is also possible that some processors may have incorrect values in min/max
registers caused by error in manufacturing process. Probably it would be BIOS
job to set them to right frequency and P-States tables would have correct
values inside.
Two additional sanity checks for voltage.
Signed-off-by: Rafał Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
Viresh Kumar