On Wednesday 25 January 2017 17:11:27 Hans de Goede wrote: > Some LEDs may have their brightness level changed autonomously > (outside of kernel control) by hardware / firmware. This commit > adds support for an optional brightness_hw_changed attribute to > signal such changes to userspace (if a driver can detect them): > > What: /sys/class/leds/<led>/brightness_hw_changed > Date: January 2017 > KernelVersion: 4.11 > Description: > Last hardware set brightness level for this LED. Some LEDs > may be changed autonomously by hardware/firmware. Only LEDs > where this happens and the driver can detect this, will > have this file. > > This file supports poll() to detect when the hardware > changes the brightness. > > Reading this file will return the last brightness level set > by the hardware, this may be different from the current > brightness. > > Drivers which want to support this, simply add LED_BRIGHT_HW_CHANGED to > their flags field and call led_classdev_notify_brightness_hw_changed() > with the hardware set brightness when they detect a hardware / firmware > triggered brightness change. > > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Just speculation: What about using name 'actual_brightness'? It provides same output on read as actual_brightness from /sys/class/backlight/. -- Pali Rohár pali.rohar@xxxxxxxxx