On 11/20/2016 03:56 AM, Ralf Mardorf wrote:
Are you using the "helper script" because
sudo echo $(luminance) > "$dest"/brightness
doesn't work? If so, then consider to use
echo $(luminance) | sudo tee "$dest"/brightness
to get rid of the "helper script".
Regards, Ralf
Thanks Ralf, Yes, tee redirected into /dev/null to suppress the tee output works as does: su -c 'command ...' or sudo sh -c 'command ...' I noted the use of su -c in the original (the only extra steps there are tweaking /etc/pam.d/su). I had the helper from manually setting the brightness, e.g. sudo nvhelper.sh level (and it's a lot easier to explain "use a helper" than bog down in a discussion of why in 'sudo echo X > file' sudo only applies to 'echo' :) Whatever you like best to insure redirection is done as root. I'm just glad to have a working backlight with the nvidia driver. Now if I can just convince myself to stomach plasma/fw5... easier said than done... I also think there is probably a way to write a udev rule that does the monitoring of acpi_video0 and changes nvidia_backlight as well. I just haven't had time to explore that one. That would probably be the cleanest way of doing it. This HP laptop has been full of more surprises than I've ever had before in Linux. My previous 3 laptops have all be Toshibas, and Dell before that. No problems with any of them. (although I did have to use acpi_video0 for brightness after the whatever version upgrade to X broke backlight control for that model a couple of years ago) This laptop still won't boot grub, but everything else works wonderfully. (the new squished screen at 1600x900 takes getting used to as I could see more, clearer at 1440x900 on the old one, and the physical dimensions of the old screen were actually larger than this one) -- David C. Rankin, J.D.,P.E.