Brightness controls of my Lenovo laptop have no effect

Hello everyone,

I am using Fedora for the first time. Everything works perfectly so far, except a small issue with the brightness controls. Brightness is always at maximum in my laptop and I can’t change it. Brightness control keys respond and I can see the brightness bar goes up or down, but this has no effect. It always works at maximum.

I followed the solution in this thread but it did not work for me.

This laptop is a Lenovo Legion 5 (82B1000AUS) with AMD Ryzen™ 7 4800H Processor (2.90 GHz, up to 4.20 GHz Max Boost, 8 Cores, 16 Threads, 8 MB Cache) and NVidia Geforce GTX 1660 Ti.

Fedora 35 with Gnome
Linux version: 5.17.4-200.fc35.x86_64

I am not sure if they are related, but following error lines are from my dmesg output:

[   37.473611] nvidia-gpu 0000:01:00.3: i2c timeout error e0000000
[   37.473621] ucsi_ccg 20-0008: i2c_transfer failed -110
[   37.473626] ucsi_ccg 20-0008: ucsi_ccg_init failed - -110
[   37.473631] ucsi_ccg: probe of 20-0008 failed with error -110
...
[    1.867037] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:00/LNXVIDEO:00/input/input4
[    1.867166] ACPI: video: Video Device [VGA] (multi-head: yes  rom: no  post: no)
[    1.867231] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PCI0.GP17.VGA.LCD._BCM.AFN7], AE_NOT_FOUND (20211217/psargs-330)
[    1.867239] ACPI Error: Aborting method \_SB.PCI0.GP17.VGA.LCD._BCM due to previous error (AE_NOT_FOUND) (20211217/psparse-529)
[    1.867248] ACPI: \_SB_.PCI0.GP17.VGA_.LCD_: _BCM evaluation failed

This brightness level hurts my eyes, I can’t comfortably use my computer for more than a few minutes.

Any help will be appreciated.

2 Likes

Here are some additional information I collected by following this thread:

Output of ls /sys/class/backlight/:
nv_backlight

Output of usr/sbin/lspci -k | grep -A 3 VGA:

01:00.0 VGA compatible controller: NVIDIA Corporation TU116M [GeForce GTX 1660 Ti Mobile] (rev a1)
	Subsystem: Lenovo Device 3a46
	Kernel driver in use: nouveau
	Kernel modules: nouveau
1 Like

I see you are using the Nouveau driver. Maybe using the proprietary driver that Nvidia provides would be worth a go to see if that helps?

https://rpmfusion.org/Howto/NVIDIA

Hey,

have you tried out using different kernels? I posted a similar question (which you referenced), and found that on some kernels the brightness control works and others it does not.

More specifically: on 5.14.10-300.fc35 (and previous), the brightness control works, then for newer kernels, it does not work until 5.17.7-200.fc35, where it’s working again. Also, on Fedora 36 with kernel 5.17.7-300.fc36 brightness control keys work, as well.

This does not fix the problem, but at least solves it.

1 Like