optimus, random freeze without nomodeset, no backlight support with nomodeset

English Hardware
1

hi,

I recently had at work an HP zbook 15 G3 (dual graphic cards: intel integrated and nvidia quadro)
I had first Ubuntu with plasma desktop installed by the lab (worked ok except with second screen and docking station), which i decided to replace by Opensuse Leap 42.1, with plasma too.

First, I could not install without passing the nomodeset option to the kernel. With nomodeset, installation went fine, and when i rebooted, i saw that i had no way to control screen brightness / backlight, which was at a painful maximum. Not with the applet, nor with the fn keys. The /sys/class/backlight was empty.

I decided to go on and install bumblebee with nvidia proprietary drivers. (blacklisted nouveau, mkinitrd, etc). So far no problems, bumbleebe worked fine, but still no backlight control. The /sys/class/backlight was empty.

If i removed the nomodeset from the kernel options, (keeping nouveau.modeset=0 and nouveau in the blacklist), then i would see intel_backlight in /sys/class/backlight, and could control backlight from the applet. I discovered later that the module i915 is needed for this to happen (tried to see with i915.modeset=0/1)
Nevertheless, after 3 to 15 min maximum, the desktop would ranomly freeze: the mouse would stutter twice, then everything would freeze: no mouse or keyboard control, had to reset with power button.

Same behavior with nouveau without bumblebee: as soon as i remove nomodeset, the crash is bound to happen.

I have a temporary work around now, where I disable integrated graphics in the bios, and installed the binary driver from the nvidia website, while still booting with nomodeset option. /sys/class/backlight now contains acpi_video0, and control works only through the applet.

There is no error in xorg log, nor in journalctl, except spamming " kscreen: Primary output changed from blablabla", which still happens now.

I’m at loss to find the culprit, especially because it worked in Ubuntu.
How can i find which modeset doesn’t please my configuration ? I would really appreciate the optimus technology for battery life and heat.

thanks !

2

The graphical backlight is enabled using /etc/default/grub

Add the following line to GRUB_CMDLINE_LINUX in /etc/default/grub

acpi_backlight=video acpi_osi=Linux

Next, run grub2-mkconfig -o /boot/grub2/grub.cfg to update the changes to /etc/default/grub

Install xbacklight. This package is used to increase or decrease the brightness.
Reboot your laptop.

FYI

xbacklight - Utility to adjust the screen backlight brightness

Xbacklight is used to adjust the backlight brightness where supported. It uses the RandR extension to find all outputs on the X server supporting backlight brightness control and changes them all in the same way.

I also encourage that you use suse-prime as a replacement to bumblebee. It allows you to use the drivers downloaded from the Nvidia website.

3

hi,

I indeed didn’t try acpi_backlight=video, while keeping nomodeset.
I shall give it a try.

As for suse prime, it seems it’s not in the 42.1 repos. I’ll wait for 42.2. Never the less, it seems (?) to require to log in/out while switching , while bumblebee doesn’t, which I find very nice.

thanks

4

According to my notes on HP laptops the following applies:

Add the following line to GRUB_CMDLINE_LINUX in /etc/default/grub

acpi_backlight=video acpi_osi=Linux

Please do not add them one at a time. They must be added as shown above.

Leap 42.2 is right around the corner while 42.2 RC1 is available for download right now.

5

Update

I have a link providing suse-prime for openSUSE 42.1 below:](http://download.opensuse.org/repositories/home:/bosim:/suse-prime/openSUSE_Leap_42.1/)
http://download.opensuse.org/repositories/home:/bosim:/suse-prime/openSUSE_Leap_42.1/

6

https://forums.opensuse.org/showthread.php/505270-ultimate-tutorial-installing-Bumblebee-driver-for-SUSE