Tried "acpi_backlight=vendor" and "video.use_native_backlight=1", the bug still exists.
Tried to downgrade BIOS mentioned in https://bugs.launchpad.net/stella/hwe-stella/+bug/1023760/comments/12 Failed to reflash the BIOS. And I can't access the BIOS mentioned in https://bugs.launchpad.net/stella/hwe-stella/+bug/1023760/comments/24 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1152544 Title: HP Envy 23 AIO - No way to dim display To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1152544/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs