#[Solved] Trouble having backlight work on my laptop

1 messages · Page 1 of 1 (latest)

devout aurora
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Hello, just started a fresh install and I'm trying to get my backlight to work on my laptop.

When I try to change the brightness there's a visible change in number on my status bar but the brightness itself does not change. I have systemctl installed and the status bar changes when I press the brightness hotkeys, that is not the issue.

Ive already went to the backlight page on the arch wiki. When I go to /sys/class/backlight I find that it only registers my nvidia card and not my intel integrated graphics.

Ive attemtped all the troubleshooting methods listed, by first going to the grub bootloader file and adding acpi_backlight= and selecting the parameters lists. Then I tried disabling nomodeset and then adding acpi_backlight= and still the brightness doesnt visibly change. I have made sure to regenerate the grub bootloader file every time.

My laptop is an Acer Predator Helios Neo 16. Its an Optimus laptop and Ive enabled nvidia prime. If someone could help thatll be wonderful, cause I prefer working in dark spaces and dont wanna be flashbanged when browsing stuff lol

dusky terrace
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just to confirm, you've tried removing nomodeset and each of the 4 settings for acpi_backlight (video, native, vendor, nvidia_wmi_ec). does /sys/class/backlight change for all 4 combos?

devout aurora
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On all combos nvidia_wmi_ec was available but not intel, which are the graphics powering my DE

dusky terrace
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try having the kernel identify itself as the latest supported windows in your bios by running mkdir ssdt; cd ssdt; sudo acpidump -b && for i in *; do echo $i:; strings -a $i | grep -i windows; done and identifying the highest windows version, e.g. Windows 2021. Then at boot manually apppend acpi_osi="Windows <your highest version>" nohpet. afterwards, check /sys/class/backlight, and for what you have in there, e.g. nvidia, cd there, then cat max_brightness and set brightness to something lower like sudo -u root bash -c "echo 100 > brightness" and see if that actually makes a difference

devout aurora
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Hold on, is this trying to lie to the laptop we are running Windows? I'll give it a shotb

dusky terrace
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yeah, it's to get it to declare itself as Windows <version> so that it has the same acpi methods available to it that Windows would have to see if that has any effect. do it by hitting e in your bootloader though and also setting nohpet, as I've had timer issues when doing that. Afterwards, try te cat and echo on your /sys/class/backlight/<vendor> folder and see if that makes a difference, or if the /sys/class/backlight/<vendor> folder changes as well

devout aurora
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Changed it , didn't do a thing

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Thanks for the attempt tho

devout aurora
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Hold on theres something wierd.
Im using wayland compositor right, and it doesnt show me using the GBM backend
because when I type in `journalctl -b 0 --grep "renderer for" theres no entries.
DRM kernel mode setting should have modeset on, cause I checked it. I also added the envorpnemnt cairables long ago so I dont knwo whats happening here. I might’ve missed somwthing, not sure

dusky terrace
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which de/wm are you using? you can check your env variables by typing in printenv lets see both

devout aurora
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sure! I'm current using Hyprland which is a wm right?
anyways, here's all my env variables. Nothing sus here

📎 env.text
dusky terrace
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i think you're good. have time for a call today to look over this stuff?

devout aurora
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Only checked this thread just as I was about to sleep. Do you mind waiting ~8 hours ? If not, I should be available after.

dusky terrace
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of coufse, just let me know when once best for you and we'll shcedule some tije whhen you're ready

devout aurora
dusky terrace
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cool right now work for you ?

devout aurora
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in VC rn

dusky terrace
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crud i missed t

devout aurora
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@dusky terrace You wanna move to another VC

dusky terrace
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GBM_BACKEND

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__GLX_VENDOR_LIBRARY_NAM

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~./.profile

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nvidia-drm and nvidia

dusky terrace
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hey billy, just sumarizing our call. we checked your nvidia srettings and set the boot parameters based on the wiki. i suggested we try a linux mint usb to see where we're at as this as worked fine beforehand. let me know if you need any help in cnfirugiuration between these two

devout aurora
# dusky terrace hey billy, just sumarizing our call. we checked your nvidia srettings and set t...

Hey lionel, sorry to have wasted your time. So, turns out, all I needed to do was the parameter acpi_backlight=native. The reason that I didn't fix this sooner was because I didn't know how to set kernel parameters. I thought you were meant to append the parameters at the end of the file. Luckily you told me made me put in some other kernel parameters and then I put two and two together. Thanks for your help!

steel garnetBOT
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