Arch Linux

Quarzstufenhyäne

Member

Registered: 2016-11-29

Posts: 4

Optimus Laptop - Power management with PRIME

Hi,

I own a "TUXEDO Book XC1507". This is a fairly new Optimus laptop, so it has the HDMI and Mini-DP outputs wired to the Nvidia card.
Therfore I can't just disable that  card in BIOS, but have to stick with "MS-Hybrid".

Until recently, I've successfully used Bumblebee with the proprietary Nvidia driver. However, it had some issues: brightness control didn't work, always typing "intel-virtual-output" was annoying, proprietary software is bad, and so on...

Now after switching to nouveau, I see both graphics cards in "xrandr --listproviders" and need no more "intel-virtual-output", so that's a plus.
Manual power management with writing "\_SB.PCI0.PEG0.PEGP._OFF" to "/proc/acpi/call" still works as if I was using bbswitch.
That means I have twice the lifetime if the Nvidia card is off.
However, the automatic method fails.
The "/sys/kernel/debug/vgaswitcheroo/switch" lists

0:IGD: :Pwr:0000:00:02.0
1:DIS:+:DynOff:0000:01:00.0

and switching between "DynOff" and "DynOn" works e.g. if I do "DRI_PRIME=1 glxinfo" (although it sometimes remains "DynOn" after I disconnect an external monitor, but that's another story...)
but the power consumption only decreases by ca. 20 % when switching off (in contrast to 50%) and the fans keep running!
Also, I cannot interact with it by echoing anything to "switch" - "IGD" will do nothing, while "OFF" causes a system freeze.

Brightness control doesn't work with nouveau either, but that's not my main problem (it has never worked in "MS-Hybrid" mode, not even on Windows xD, though it works in "Discrete" mode [Nivida card only])

I'll directly show my Xorg config files, as they are so short:

/etc/X11/xorg.conf.d/20-intel.conf

Section "Device"
    Identifier     "intelgpu0"
    Driver         "intel"
    Option         "XvMC" "true"
    Option         "UseEvents" "true"
    Option         "TearFree" "true"
    BusID          "PCI:0:2:0"
    Option         "Backlight" "intel_backlight"
EndSection

/etc/X11/xorg.conf.d/20-nouveau.conf

Section "Device"
    Identifier "Nvidia Card"
    Driver "nouveau"
    BusID "PCI:01:00:0"
    Option "DRI" "3"
EndSection

Both drivers (i915, nouveau) are loaded on boot, while Nvidia is blacklisted.
Bumblebeed.service is disabled, bbswitch is not load.
Vgaswitcheroo.service (from AUR) is enabled and exits normally (I guess it only turns off the Nvidia card on boot).

Has anyone managed to get such an Optimus setup running? Any help would be appreciated.

Thanks a lot in advance!