cpufreq: Add CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING cpufreq driver flag

The policy->transition_latency field is used for multiple purposes
today and its not straight forward at all. This is how it is used:

A. Set the correct transition_latency value.

B. Set it to CPUFREQ_ETERNAL because:
   1. We don't want automatic dynamic switching (with
      ondemand/conservative) to happen at all.
   2. We don't know the transition latency.

This patch handles the B.1. case in a more readable way. A new flag for
the cpufreq drivers is added to disallow use of cpufreq governors which
have dynamic_switching flag set.

All the current cpufreq drivers which are setting transition_latency
unconditionally to CPUFREQ_ETERNAL are updated to use it. They don't
need to set transition_latency anymore.

There shouldn't be any functional change after this patch.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar
2017-07-19 15:42:48 +05:30
committed by Rafael J. Wysocki
parent 560c6e452d
commit fe829ed8ef
11 changed files with 26 additions and 18 deletions

View File

@@ -442,7 +442,8 @@ static struct cpufreq_driver pmac_cpufreq_driver = {
.init = pmac_cpufreq_cpu_init,
.suspend = pmac_cpufreq_suspend,
.resume = pmac_cpufreq_resume,
.flags = CPUFREQ_PM_NO_WARN,
.flags = CPUFREQ_PM_NO_WARN |
CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.attr = cpufreq_generic_attr,
.name = "powermac",
};
@@ -626,14 +627,16 @@ static int __init pmac_cpufreq_setup(void)
if (!value)
goto out;
cur_freq = (*value) / 1000;
transition_latency = CPUFREQ_ETERNAL;
/* Check for 7447A based MacRISC3 */
if (of_machine_is_compatible("MacRISC3") &&
of_get_property(cpunode, "dynamic-power-step", NULL) &&
PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
pmac_cpufreq_init_7447A(cpunode);
/* Allow dynamic switching */
transition_latency = 8000000;
pmac_cpufreq_driver.flags &= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
/* Check for other MacRISC3 machines */
} else if (of_machine_is_compatible("PowerBook3,4") ||
of_machine_is_compatible("PowerBook3,5") ||