Incorrect sysfs file is used for backlight control
I'm porting Ubuntu Touch to the Xiaomi Redmi K20 Pro. There are two subdirectories in /sys/class/backlight
on my device - backlight
, and panel0-backlight
. panel0-backlight
is the display backlight.
Repowerd's current method of choosing the sysfs file to control the backlight with is to iterate through the subdirectories in /sys/class/backlight
, looking for one with a brightness
file.
In my case, this applies to both subdirectories. backlight
comes before panel0-backlight
alphebetically, so the former is used instead of the latter - which is not what should happen.
To fix this, I have two suggestions:
- Code some sort of prioritisation logic, to make sure the right backlight device is chosen, or
- Let the path be configured in a config file.
1 seems cleaner (if it can be done), as it should work automatically.
Edited by Flo Lee