cpufreq: Update Documentation for cpus and related_cpus

Documentation related to cpus and related_cpus is confusing and not very clear.
Over that CPUFreq core has seen much changes recently. Lets update documentation
and comments for cpus and related_cpus.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2013-01-31 02:03:53 +00:00 committed by Rafael J. Wysocki
parent 5553f9e26f
commit 951fc5f458
3 changed files with 14 additions and 6 deletions

View file

@ -111,6 +111,12 @@ policy->governor must contain the "default policy" for
For setting some of these values, the frequency table helpers might be
helpful. See the section 2 for more information on them.
SMP systems normally have same clock source for a group of cpus. For these the
.init() would be called only once for the first online cpu. Here the .init()
routine must initialize policy->cpus with mask of all possible cpus (Online +
Offline) that share the clock. Then the core would copy this mask onto
policy->related_cpus and will reset policy->cpus to carry only online cpus.
1.3 verify
------------

View file

@ -190,11 +190,11 @@ scaling_max_freq show the current "policy limits" (in
first set scaling_max_freq, then
scaling_min_freq.
affected_cpus : List of CPUs that require software coordination
of frequency.
affected_cpus : List of Online CPUs that require software
coordination of frequency.
related_cpus : List of CPUs that need some sort of frequency
coordination, whether software or hardware.
related_cpus : List of Online + Offline CPUs that need software
coordination of frequency.
scaling_driver : Hardware driver for cpufreq.

View file

@ -89,8 +89,10 @@ struct cpufreq_real_policy {
};
struct cpufreq_policy {
cpumask_var_t cpus; /* CPUs requiring sw coordination */
cpumask_var_t related_cpus; /* CPUs with any coordination */
/* CPUs sharing clock, require sw coordination */
cpumask_var_t cpus; /* Online CPUs only */
cpumask_var_t related_cpus; /* Online + Offline CPUs */
unsigned int shared_type; /* ANY or ALL affected CPUs
should set cpufreq */
unsigned int cpu; /* cpu nr of CPU managing this policy */