On 11/17/2016 04:31 PM, David C. Rankin wrote:
All,
Laptop: HP 8760w, Quadro 3000M, nvidia-340xx packages.
The driver works perfectly (no errors in Xorg.0.log), but I have no way to control the screen brightness. I've followed the suggestions in:
https://wiki.archlinux.org/index.php/NVIDIA/Tips_and_tricks
but I still have no backlight control. Using the laptop function keys, the values in /sys/class/backlight/acpi_video0/brightness are properly set, e.g.
$ cat /sys/class/backlight/acpi_video0/brightness 8
(now tap the [func][F9], brightness lower, twice)
$ cat /sys/class/backlight/acpi_video0/brightness 6
(actual_brightness value tracks brightness)
$ cat /sys/class/backlight/acpi_video0/max_brightness 20
This works with OR without /etc/X11/xorg.conf.d/20-nvidia.conf:
Option "RegistryDwords" "EnableBrightnessControl=1"
Does anyone have any suggestions on anything else to try before I start loading the aur nvidia-bl or nvidiabl packages? I don't mind adding more software, but if there are a few more tweaks to try before going that route, I would like to try them first. Anybody get backlight working with a similar model laptop?
Let me add to this, that powerdevil is seeing the screen brightness changes and Udev is evidently applying them correctly. For example, pressing the function key to raise/lower brightness seems to generate the correct log entries: Nov 17 23:36:37 seidr org_kde_powerdevil[710]: powerdevil: Screen brightness value: 6 Nov 17 23:36:37 seidr org_kde_powerdevil[710]: powerdevil: Screen brightness value max: 20 Nov 17 23:36:37 seidr dbus[334]: [system] Activating service name='org.kde.powerdevil.backlighthelper' (using servicehelper) Nov 17 23:36:37 seidr org_kde_powerdevil[710]: powerdevil: set screen brightness value: 7 Nov 17 23:36:37 seidr org_kde_powerdevil[710]: powerdevil: Screen brightness value max: 20 Nov 17 23:36:37 seidr dbus[334]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper' Nov 17 23:36:37 seidr org_kde_powerdevil[710]: powerdevil: Udev device changed "/sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0" "/sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0" And, as noted above, the values in /sys/class/backlight/acpi_video0/brightness are changing as they should. I'll give both the aur packages a try (I have both built -- but the nvidiabl package is currently disowwned and needs a maintainer if anyone is interested) -- David C. Rankin, J.D.,P.E.