On November 18, 2016 6:42:40 AM GMT+01:00, "David C. Rankin" <drankinatty@xxxxxxxxxxxxxxxxxx> wrote: >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) Do you use any special kernel boot parameters? Using "acpi_backlight=vendor" helped me in a similar situation, though it was about another option interfering with backlight control. Sylvain
