Power — runtime power profile management¶

Source: framework/library/power.sh

Runtime power profile management for labctl. Switches the cpufreq governor and USB autosuspend settings on the running system. All functions require the framework to be sourced before this file.

Requires: config module, systemctl (for power::set_profile), root privileges (for power::apply_profile).

Profiles¶

The active profile is persisted to /data/config/power/profile. On boot, power-profile.service reads it and calls power::apply_profile. If no profile is stored, balanced is used.

CLI¶

labctl power [get]        # show active profile
labctl power set <name>   # persist and apply a profile
labctl power apply        # re-apply persisted profile (called at boot)
labctl power list         # list available profiles

Functions¶

power::list_profiles¶

Listing available profiles

Prints the three profile names, one per line.

power::is_valid_profile <name>¶

Validating profile: \<name>

Returns 0 if name is one of performance, balanced, saver. Returns 1 otherwise.

power::get_profile¶

Reading current profile

Reads the profile from /data/config/power/profile. Returns balanced if no profile is stored.

power::apply_profile <name>¶

Applying profile: \<name>

Writes the cpufreq governor and USB autosuspend settings for the named profile to sysfs. Requires root — intended to be called by power-profile.service or as root directly. Fails with return code 1 for an unknown profile name.

Sysfs paths written: - $POWER_CPUFREQ_PATH/policy*/scaling_governor - $POWER_USB_PATH/*/power/control - $POWER_USB_PATH/*/power/autosuspend_delay_ms

Both path variables default to the standard kernel sysfs locations and can be overridden in tests.

power::set_profile <name>¶

Setting profile: \<name>

Persists the named profile to /data/config/power/profile, then restarts power-profile.service to apply it. The service runs as root so no direct sysfs access is required from the caller.