On 7/8/24 4:23 AM, Masaru Nomiya wrote:
How about this?
1. acpi_backlight=native
or
2. acpi_backlight=video
We have a winner!!! No. 2 did in fact work, e.g.: 14:06 wizard:~> l /sys/class/backlight/ total 0 drwxr-xr-x 2 root root 0 Jul 8 14:07 . drwxr-xr-x 68 root root 0 Jul 8 14:06 .. lrwxrwxrwx 1 root root 0 Jul 8 14:06 acpi_video0 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0 14:07 wizard:~> bl Current Brightness: 7 (0-20) 14:07 wizard:~> cat /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-6.9.7-1-default root=UUID=17f7b9ba-8760-4a74-bcc3-3f4ff0908233 splash=silent quiet security=apparmor mitigations=off nosimplefb=1 acpi_backlight=video 14:07 wizard:~> "native" and "vendor" produced no acpi_video0 in /sys/class/backlight, e.g. 13:59 wizard:~> l /sys/class/backlight total 0 drwxr-xr-x 2 root root 0 Jul 8 13:59 . drwxr-xr-x 68 root root 0 Jul 8 13:58 .. 13:59 wizard:~> cat /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-6.9.7-1-default root=UUID=17f7b9ba-8760-4a74-bcc3-3f4ff0908233 splash=silent quiet security=apparmor mitigations=off nosimplefb=1 acpi_backlight=native 13:59 wizard:~> Thank you Masaru and thank goodness it wasn't something in the binary part of the driver. -- David C. Rankin, J.D.,P.E.