Hello, the backlight control no longer works on my ASUS UM325 (Ryzen 5700U) OLED laptop. I have bisected the breakage to commit 7fd13baeb7a3a48. commit 7fd13baeb7a3a48cae12c36c52f06bf4e9e7d728 (HEAD, refs/bisect/bad) Author: Alex Deucher <alexander.deucher@xxxxxxx> Date: Thu Jul 8 16:31:10 2021 -0400 drm/amdgpu/display: add support for multiple backlights On platforms that support multiple backlights, register each one separately. This lets us manage them independently rather than registering a single backlight and applying the same settings to both. v2: fix typo: Reported-by: kernel test robot <lkp@xxxxxxxxx> Reviewed-by: Roman Li <Roman.Li@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> I have encountered another user with the same issue on reddit[0]. The node in /sys/class/backlight exists, writing to it just does nothing. I would be glad to help debugging the issue. Thank you very much. Regards, Samuel Čavoj [0]: https://www.reddit.com/r/AMDLaptops/comments/qst0fm/after_updating_to_linux_515_my_brightness/