Another potentially duplicate report has a possible workaround: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161148/comments/5
Adding "i915.enable_dpcd_backlight=0" to the Linux kernel command line worked around the problem for me. Machine: Dell Latitude 7490 GPU: Intel UHD Graphics 620 (Kaby Lake-R GT2) OS: Kubuntu 26.04 Kernel: 7.0.0-28-generic Confirming here that the i915.enable_dpcd_backlight=0 worked: - Full brightness achieved - control over brightness retained, even with 7.0.0-28 kernel. See above link for more details about potential cause. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2161102 Title: Regression: Intel TigerLake eDP backlight broken after Linux 7.0.0-27 (Dell Latitude 5420) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161102/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
