Backlight after suspend at 100% brightness (Acer Predator PH317-56, RTX 3070, MUX)

Graphics / Linux Linux
1

I’m using Fedora (38-40) but doubt it’s distro related. I have also tried the nouveau driver by blacklisting nvidia.

I can set the brightness of the display after a clean boot without issue:
Initial

(base) [nvidia_wmi_ec_backlight]$ cat actual_brightness
254
(base) [nvidia_wmi_ec_backlight]$ cat brightness
254
(base) [nvidia_wmi_ec_backlight]$ cat bl_power
0
(base) [nvidia_wmi_ec_backlight]$ cat max_brightness
255
(base) [nvidia_wmi_ec_backlight]$ cat type
firmware

Brightness set to 50% via KDE (brightnessctl et al equally work)

(base) [nvidia_wmi_ec_backlight]$ cat actual_brightness
128
(base) [nvidia_wmi_ec_backlight]$ cat brightness
128

After sleep

(base) [nvidia_wmi_ec_backlight]$ cat actual_brightness
254
(base) [nvidia_wmi_ec_backlight]$ cat brightness
128

If I then try to change the brightness up or down a “hi-res flickering” occurs is the best way I can describe it. This is not a PWM display: https://laptopmedia.com/gb/review/acer-predator-helios-300-ph317-56-review/#p6

After much searching I have tried the following:

nvidia-drm modeset=1 – Already set
nvidia.NVreg_RegistryDwords=EnableBrightnessControl=1

  • No change

acpi_backlight=video

  • acpi_video0, acpi_video1, acpi_video2
  • Values of “brightness” and “actual_brightness” change but the screen brightness does not.

acpi_backlight=vendor

  • No backlight in /sys/class/backlight/
  • Appears to be pinned at 100% brightness

acpi_backlight=native

  • intel_backlight, nvidia_0
  • nvidia_0 values change but the screen does not
  • intel_backlight values change but the screen does not

I’ve also updated the BIOS to the latest.

Is there any more information needed or any suggestions?

±----------------------------------------------------------------------------------------+
| NVIDIA-SMI 550.78 Driver Version: 550.78 CUDA Version: 12.4 |
|-----------------------------------------±-----------------------±---------------------+
| GPU Name Persistence-M | Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap | Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|=========================================+========================+======================|
| 0 NVIDIA GeForce RTX 3070 … Off | 00000000:01:00.0 Off | N/A |
| N/A 37C P0 20W / 115W | 9MiB / 8192MiB | 0% Default |
| | | N/A |
±----------------------------------------±-----------------------±---------------------+

±----------------------------------------------------------------------------------------+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=========================================================================================|
| 0 N/A N/A 12242 G /usr/libexec/Xorg 4MiB |
±----------------------------------------------------------------------------------------+

nvidia-bug-report.log.after_sleep.gz (2.0 MB)
nvidia-bug-report.log.before_sleep.gz (1.7 MB)
acpidump.txt (3.5 MB)

Thanks.