595.58.03 Driver still has brightness control issue for 5070Ti mobile

NVIDIA Open GPU Kernel Modules Version

595.58.03 and all older version (595.45.04 shows here)

Please confirm this issue does not happen with the proprietary driver (of the same version). This issue tracker is only for bugs specific to the open kernel driver.

• I confirm that this does not happen with the proprietary driver package.

This happens in both Proprietary and Open Version

Operating System and Version

Ubuntu 25.10

Kernel Release

6.17.0-18-generic

Please confirm you are running a stable release kernel (e.g. not a -rc). We do not accept bug reports for unreleased kernels.

• I am running on a stable kernel release.

Hardware: GPU

NVIDIA 5070Ti

Describe the bug

Problem is:
The new 595 Driver on Linux for both Nvidia Property and MIT/GPL cannot control the brightness of screen, under Nvidia Optimus Mode (Can Only Control Under BIOS) with 5070 Ti

And the Nvidia Property Version of the Driver cannot even detect 5070Ti Mobile GPU on Linux

Add any Permutation and Combination of the bellow kernel flag like the internet suggest does not work

acpi_backlight=native/video/vendor
nvidia-drm.modeset=1
nvidia-drm.fbdev=1
i915.enable_dpcd_backlight=1/0
nvidia.NVreg_EnableBacklighthandler=1/0
nvidia.NVreg_RegistryDwords=EnableBrightnessControl=0/1
acpi_osi=! “acpi_osi=Windows 2015” / acpi_osi=Linux

Environment:
Ubuntu 25.10
Desktop Environment: KDE/Gnome (Wayland)
Kernel: 6.17.0-18-generic
CPU: Intel(R) Core™ Ultra 9 275HX (2.70 GHz)
GPU: Nvidia GeForce RTX 5070 Ti LapTop GPU
Computer: HP OMEN MAX Gaming Laptop

Hope the problem could get solved🙏.

Here are all possible logs might help,
journalctl-boot.log
dmesg.log
nvidia-smi.log

To Reproduce

Just use Nvidia Optimus Mode with Notebook, enter the KDE or Gnome, try to change the brightness of the screen, you will find you cannot change the brightness of the screen.

And for Property Version, just enter the nvida-smi in the console, you will see no device detected.

Bug Incidence

Always

nvidia-bug-report.log.gz

nvidia-bug-report.log.gz

More Info

No response

Start by reviewing the attached nvidia-bug-report.log.gz, dmesg.log, journalctl-boot.log, and nvidia-smi.log for the Ubuntu 25.10 Optimus setup. Reproduce the brightness failure in KDE or GNOME and compare the open and proprietary driver behavior. Done means brightness control works in Optimus mode and the proprietary driver detects the RTX 5070 Ti Mobile GPU.