Hi,
I have the same problem as the person in the thread of same name, but the advise, running:
sudo usermod -aG video $USER
didn’t work, and I still need to sudo the command.
Here’s what happens:
log
/s/c/backlight> light -U 20 -v 3
helpers.c:27: Error: Couldn’t parse an unsigned integer from ‘/home/drm/.config/light/targets/sysfs/backlight/auto/minimum’
helpers.c:45: Error: could not open ‘/sys/class/backlight/intel_backlight/brightness’ for writing
helpers.c:45: Error: Verify it exists with the right permissions
impl/sysfs.c:133: Error: failed to write to sysfs device
light.c:944: Error: failed to write to target
main.c:20: Error: Execution failed
Please provide the link for your hardware and explain what your issue is. Is this an issue with backlighting on the keyboard? Just because this worked for someone else’s hardware doesn’t necessarily mean it is the proper way to address the issue on your hardware.
My hardware is fine as the aforementioned command works well when prefixed with “sudo”.
It controls the screen backlight/luminosity (btw, I find it counter-intuitive that the likes of wlsunset doesn’t include that feature).
It is not a hardware issue.
I missed that aforementioned command you talk about… Can you repost it please?
Also post (in code block, if you please…):
groups | grep -wo video
ls -l /sys/class/backlight/intel_backlight/brightness
ls -l /sys/class/backlight/
grep "GROUP=\"video\"" /usr/lib/udev/rules.d/*.rules
grep "GROUP=\"video\"" /etc/udev/rules.d/*.rules
That isn’t the point. I’m trying to understand what the issue is that you are using the command for. You have the same problem you say as in the thread of the same name. This isn’t the way to post things. We aren’t mind readers and please don’t expect us to go looking through other posts to try to understand what the issue is you are having. This is just confusing. There may be some here that are familiar with what you are alluding to but not all of us.
I think I’ve being made a fool of…
I just want to change the luminosity of my bl**dy laptop’s screen, which is the point of the “light” program.
It works well when run by root, but doesn’t as a non-privileged user.
It seems close indeed, but can’t I do the same post-installation ? Otherwise what’s the point in having a “light” package if I can’t use it from a normal user ?
The OP is pretty spot on actually. They come on regularly and create nearly impossible to solve threads with minimal information, demands a bunch of help, and rarely even answers most of the questions proposed to help them. I’ll take the Vegas odds they find a solution and mark their own post as the answer that doesn’t make any sense.
We call them a . . . Well. There’s a name,I cannot say because there’s a few who get in a tizzy about it.
@sentinel166
This is the information you need to look at. The first thing i would try is a kernel parameter in the default grub command line and then update grub and reboot.
This is the one i would try first.
acpi_backlight=vendor
Add to the default grub command line in /etc/default/grub using a text editor such as nano and save the file. Then update grub with
sudo grub-mkconfig -o /boot/grub/grub.cfg
Then reboot and see if there is any difference. You may want to uninstall the light package first though.
~> sudo usermod -aG video drm
~> light -U 30
~ [1]> light -U 30 -v 3
helpers.c:27: Error: Couldn't parse an unsigned integer from '/home/***/.config/light/targets/sysfs/backlight/auto/minimum'
helpers.c:45: Error: could not open '/sys/class/backlight/intel_backlight/brightness' for writing
helpers.c:45: Error: Verify it exists with the right permissions
impl/sysfs.c:133: Error: failed to write to sysfs device
light.c:944: Error: failed to write to target
main.c:20: Error: Execution failed
~ [1]> sudo light -U 30 -v 3
helpers.c:21: Error: could not open '/etc/light/targets/sysfs/backlight/auto/minimum' for reading
helpers.c:21: Error: Verify it exists with the right permissions
I disagree.
The system works exactly as it is configured to work. The system explains what is wrong and what you need to correct.
But, it seems you either don’t want to correct it, or you don’t understand what the system says.
In any case, you might want to ask for help from someone that can understand what the system says and do as he tells you to do.
Has the trolling period started in Europe already?..
