Bug happens on ubuntu 19.10 on a dell 7520. Here's what the command lspci -k | grep -iA2 VGA returns:
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) Subsystem: Dell 3rd Gen Core processor Graphics Controller Kernel driver in use: i915 -- 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Chelsea LP [Radeon HD 7730M] Subsystem: Dell Chelsea LP [Radeon HD 7730M] Kernel driver in use: radeon -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/847001 Title: Adjusting display brightness is very slow on several Dell laptops To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/847001/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs