@ddadap: No, nvidia-460 does not fix this regression. I've just tested nvidia-driver-460 (460.32.03-0ubuntu0.18.04.1) and I observe that it still misbehaves exactly as described above for 455: The initial brightness is unusually dim and cannot be changed by any means. (Also, just like 455, some pixel garbage appears during mode switch).
Reverting to 450 restores normal brightness functionality. This regression makes nvidia-460 (and nvidia-455) unusable, and manifests on multiple modern laptops. @djve60: FYI, the (still defective) nvidia-460 packages are now available in the archive, making testing 460 pretty painless at least: To install 460: sudo apt install nvidia-kernel-common-460 nvidia-driver-460 To revert to 450: sudo apt install nvidia-kernel-common-450 nvidia-driver-450 @djve60, I recommend that you go ahead and test 460 that way to determine whether your P76 sees any benefit or still fails like my X1 Extreme. ** Summary changed: - no brightness control after update from 450 to 455 + no brightness control in {455,460} after update from 450 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to nvidia-graphics-drivers-455 in Ubuntu. https://bugs.launchpad.net/bugs/1905591 Title: no brightness control in {455,460} after update from 450 Status in OEM Priority Project: New Status in nvidia-graphics-drivers-455 package in Ubuntu: Triaged Bug description: On my Lenovo X1 Extreme with GPU: NVIDIA Corporation GP107M [GeForce GTX 1050 Ti Mobile] Updating to nvidia-driver-455 results in loss of brightness control. On boot, the laptop display brightness is somewhat less than fully bright and cannot be changed. The brightness up/down keys do pop up the gnome gui brightness widget, and /sys/class/backlight/nvidia_0/* values do change, but the actual display's brightness does not. Problem occurs with either version of nvidia-driver-455 (the archive or the ~graphics-drivers/PPA). Normal functionality returns if I downgrade to any version of nvidia-driver-450. Note also that manually applying this to /lib/systemd/system/nvidia-persistenced.service has no effect on the problem: https://github.com/hugh712/nvidia-graphics-drivers/commit/bccad5ee6444dd8c5c47ba19ea0232106a1086f5 Distributor ID: Ubuntu Description: Ubuntu 18.04.5 LTS Release: 18.04 Codename: bionic kernel: 5.4.0-54-generic #60~18.04.1-Ubuntu SMP Fri Nov 6 17:25:16 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux nvidia-driver-455: 455.38-0ubuntu0.18.04.1 To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1905591/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp