d19e470b66
When _FPS indicates variable speed fan support, the thermal cooling device for fan shows max performance state count as "max_state" (greater than or equal to 1). But the thermal cooling device doesn't expose the properties of each performance state. This is not enough for smart fan control user space software, which also considers speed, power and noise level. This change exposes the properties of the fan performance states in the sysfs directory of the ACPI device representing the fan, that is /sys/bus/acpi/devices/devices/INT3404:00 or /sys/bus/platform/devices/PNP0C0B:00. For example: $ ls /sys/bus/acpi/devices/INT3404\:00 description path state0 state11 state4 state7 status hid physical_node state1 state2 state5 state8 subsystem modalias power state10 state3 state6 state9 uevent uid wakeup where each state* attribute lists the properties of a fan performance state in the following format: control_percent:trip_point:speed_rpm:noise_level_mdb:power_mw $ cat /sys/bus/acpi/devices/INT3404\:00/state10 95:0:11600:47500:4500 as documented in Documentation/admin-guide/acpi/fan_performance_states.rst While at it, return the correct error code from acpi_fan_probe() when acpi_fan_get_fps() or acpi_fan_get_fif() fails. Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> [ rjw: Subject, changelog, documentation ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
16 lines
264 B
ReStructuredText
16 lines
264 B
ReStructuredText
============
|
|
ACPI Support
|
|
============
|
|
|
|
Here we document in detail how to interact with various mechanisms in
|
|
the Linux ACPI support.
|
|
|
|
.. toctree::
|
|
:maxdepth: 1
|
|
|
|
initrd_table_override
|
|
dsdt-override
|
|
ssdt-overlays
|
|
cppc_sysfs
|
|
fan_performance_states
|