Optimus IX (Clevo) and Linux Mint 19 - screen brightness problem

Hello all

I've just bought a 17.3" Optimus IX i7-8750H laptop PC with integrated Intel and discrete NVIDIA GTX 1050 Ti graphics from PC Specialist Ltd here in the UK. I believe it's based on a Clevo N850EK (?), although dmidecode reports it as N8xEJEK.

After installing with acpi=off in grub, I've managed to get Linux Mint 19 up and running. I've also installed the relevant nvidia driver (390, I think), nvidia-prime and the nvidia settings desktop utility. The machine boots and is running stable without acpi=off in grub. I can see and switch between both GPUs without problem.

I still have a few issues still to resolve, however, and the most crucial of these is the ability to adjust display brightness.

Currently, when I use the relevant keyboard functions to increase or decrease brightness, the operating system clearly recognises that I'm trying to adjust it, as the adjustments show on screen as I press the brightness up/down keys. But the brightness remains constant - except when it reaches minimum, at which point the screen goes completely black, then when I increase it again, the screen returns to full brightness.

I've tried each of the following settings in grub (followed by update-grub) without success:

acpi_backlight=vendor

acpi_backlight=video

acpi_osi=! acpi_osi='Windows 2009'

The contents of /sys/class/backlight shows intel_backlight. I've run the following command:

systemctl enable systemd-backlight@backlight:intel_backlight.service

... and it returns the message "Failed to enable unit: Unit file systemd-backlight@backlight:intel_backlight.service does not exist."

I've tried creating the sysbacklight script in the Ubuntu help pages, setting it to use intel_backlight. The script runs fine, but has no effect on the screen brightness.

Lastly, I've created a 20-intel.conf xorg conf file in the /usr/share/X11/xorg.conf.d directory containing the following:

Section "Device"
Identifier "card0"
Driver "intel"
Option "Backlight" "intel_backlight"
BusID "PCI:0:2:0"
EndSection

Before doing so, I checked that my Intel GPU is at PCI address 0:2.0 using "lspci -vnn | grep VGA -A 12".

None of this has worked, so I'm at a loss.

Can anyone suggest anything that might help, please? I'm afraid I'm still very much a linux novice, but I'm slowly finding my way around!

Much of the information above was provided by @Dennismungai for another member facing similar problems. I'm very grateful to him for indirectly assisting me too, even though I haven't yet managed to get this working

Thanks in advance

Mike

 

Hello there,

Attempt this first:

For the grub options, make sure this line is identical:

GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi=! acpi_osi='Windows 2009' blacklist=nouveau elevator=deadline drm.debug=0xe quiet splash"

Then update grub:

sudo update-grub

Then reboot and attempt to toggle backlight control.

Also, can you show me the output of:

xrandr --listproviders

 

@Dennismungai You need to pass nomodeset along with acpi quirks which you suggested above.
I also recommend OP to install linux-firmware fo best experience and then running update-grub.

 

Thank you both

@Dennismungai - I'm just trying the grub now; then I'll try with the suggestion from @Vasudev to include nomodeset.

@Vasudev - my apologies for the linux newbie question, but when you say "install linux-firmware", would I do this with "sudo apt-get install linux-firmware" ??

Thanks again, guys - I really appreciate your help.

 

Folks - I've reached a point where I think I'm going to have to run with Windows instead

I'd tried an install of Windows 10 earlier today (which went fine) and also installed all of Clevo's supplied drivers and updates. Since doing that, now when I do a Linux Mint 19 install it crashes during bluetooth installation. I'm guessing that Clevo's updates might change the firmware of the machine, but that's only a guess. I had no such problems in my previous attempts to install Linux

Many thanks again for your help.

 

Use synaptic package manager and type linux-firmware and install it.

Do you use AMI Aptio 5 Bios or insyde h20 bios?

 

It's AMI Aptio...

 

Have you tried with just nomodeset?

 

Edit: GRUB_CMDLINE_LINUX_DEFAULT="elevator=deadline quiet splash i915.alpha_support=1 acpi_osi=linux acpi_backlight=vendor "
GRUB_CMDLINE_LINUX=""


That's how my grub is setup after a cr** of trial and error I believe the "acpi_osi=linux acpi_backlight=vendor" is what allowed me to set keyboard shortcuts to control screen brightness.

 

If what you have in your signature is the machine you're running Linux on, please drop the acpi_osi=linux line such that it looks like this:

GRUB_CMDLINE_LINUX_DEFAULT="elevator=deadline quiet splash i915.alpha_support=1
acpi_osi=! acpi_osi='Windows 2009' acpi_backlight=vendor "

Using acpi_osi=linux is not recommended. Infact, Linux, by default, responds "false" to that specific _OSI query.