Also affected on an Acer Nitro ANV15-51 (Raptor Lake iGPU driving the eDP panel, hybrid with RTX 3050, Ubuntu, dual-boot with Windows where brightness works fine).
Fresh install with kernel 7.0.0-14-generic: brightness control works. After upgrading to 7.0.0-28-generic and rebooting: brightness is stuck at maximum. The sysfs value in /sys/class/backlight/intel_backlight is accepted (e.g. 2128/32767) but the panel ignores it. Confirmed the workaround from this thread works on my machine: adding i915.enable_dpcd_backlight=0 to GRUB_CMDLINE_LINUX_DEFAULT fully restores brightness control on 7.0.0-28. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2161359 Title: linux-modules-7.0.0-28-generic breaks backlight control on some laptops To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161359/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
