korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-11 21:38:32 +08:00
Code Issues Packages Projects Releases Wiki Activity

acpi-cpufreq: Add comment under ACPI_ADR_SPACE_SYSTEM_IO case

Browse Source 
policy->cur is now set by cpufreq core when cpufreq_driver->get() is defined and
so drivers aren't required to set it. When space_id is ACPI_ADR_SPACE_SYSTEM_IO
for acpi cpufreq driver it doesn't set ->get to a valid function pointer and so
policy->cur is required to be set by driver.

This is already followed in acpi-cpufreq driver. This patch adds a comment
describing why we need to set policy->cur from driver.

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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 2013-10-16 23:58:10 +02:00 committed by Rafael J. Wysocki
parent 076dec90fc
commit 1bab64d50e
1 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/cpufreq/acpi-cpufreq.c
View File

@ -837,7 +837,12 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
switch (perf->control_register.space_id) {
case ACPI_ADR_SPACE_SYSTEM_IO:
/* Current speed is unknown and not detectable by IO port */
/*
* The core will not set policy->cur, because
* cpufreq_driver->get is NULL, so we need to set it here.
* However, we have to guess it, because the current speed is
* unknown and not detectable via IO ports.
*/
policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
break;
case ACPI_ADR_SPACE_FIXED_HARDWARE: