On 01/25/2017 05:49 PM, Pali Rohár wrote: > 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/. This name is ambiguous. Propagating it to the LED subsystem only because it exists in backlight is not sufficient argument IMHO. -- Best regards, Jacek Anaszewski
