How to switch off dgpu with nouveau

Just installed leap 15 on a laptop with nvidia optimus card.

Before, i was runing leap 42.2, and everything went smooth with nouveau.
The machine was switching from the discrete nvidia gpu and the intel integrated gpu silently without any action from me.
The leds on the laptop was indicating that the discrete nvidia gpu was turned off when not needed and turned on when necessary.
It was installed without any configuration from me.
Most important : the temperature and battery consumption was reasonable.

And now the leds on the laptop indicate that the discrete nvidia gpu is always on.
Disappointment : the temperature and battery consumption is high :frowning: :frowning:

I tried to follow this :
https://nouveau.freedesktop.org/wiki/Optimus/
But it did not work.

Initially, i realised that the intel driver for x was not installed. I had to install manually the xorg intel drivers and other things like : nf86-video-intel, and xf86-video-nv … Don’t which one is doing what…

I also tried to install the switcheroo pakages and activated the service, but no joy.

Yet, it still doesn’t work and i am asking for your help.

Thank you ;o)

Most Intel gfx users have no need for xf86-video-intel, which hasn’t had an official updated release in over 3 years. Intel gfx developers apparently put most of their time into the modesetting driver incorporated in the X server, which is why xf86-video-intel is commonly not installed. xf86-video-nv is only for antique NVidia gfx, more than somewhere around 12+ years old, long before Optimus first appeared. The modesetting driver should work for both Optimus GPUs for those who don’t demand non-FOSS drivers for their games.

How did you install? Clean install or upgrade from 42.2?

Before, i was runing leap 42.2, and everything went smooth with nouveau.
The machine was switching from the discrete nvidia gpu and the intel integrated gpu silently without any action from me.
The leds on the laptop was indicating that the discrete nvidia gpu was turned off when not needed and turned on when necessary.
It was installed without any configuration from me.

There was no such feature on a default install of 42.2, so either somebody configured that or you are not telling the whole story…

Most important : the temperature and battery consumption was reasonable.

And now the leds on the laptop indicate that the discrete nvidia gpu is always on.
Disappointment : the temperature and battery consumption is high :frowning: :frowning:

I tried to follow this :
Optimus · freedesktop.org
But it did not work.

Initially, i realised that the intel driver for x was not installed. I had to install manually the xorg intel drivers and other things like : nf86-video-intel, and xf86-video-nv … Don’t which one is doing what…

I also tried to install the switcheroo pakages and activated the service, but no joy.

On a default install of LEAP 15 on an Optimus laptop discrete graphics is normally off and can be used by issuing “DRI_PRIME=1 <command>”.
xf86-video-intel, and xf86-video-nv are not needed, vga-switcheroo is not needed, so apparently you have been looking for trouble.
Maybe restarting from scratch with a clean install is the easiest way forward unless you can undo what you did after the default install.
Please show the result of:

/sbin/lspci -nnk | grep -EiA3 'vga|3d|display'

and describe further your HW if possible, maybe you are using an unusual model or configuration.

Sorry for my late reply, due some accident in life.

So.

It is a clean install.

No. Really. Everything was working out of the box after 42.2 clean install.

And modesetting was installed by default did not switch off dgpu automatically on opensuse 15.0 .

We cannot help if we don’t understand what HW you are using, please provide the above info.

Wilco .
Didn’t have time till now. Will try later in the night.

Here you are :


--chris@machine 23:35:23 ~] /sbin/lspci -nnk | grep -EiA3 'vga|3d|display'
00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09)
        Subsystem: CLEVO/KAPOK Computer Device [1558:1550]
        Kernel driver in use: i915
        Kernel modules: i915
--
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GK107M [GeForce GT 650M] [10de:0fd1] (rev a1)
        Subsystem: CLEVO/KAPOK Computer Device [1558:1550]
        Kernel driver in use: nouveau
        Kernel modules: nouveau


Btw, i only installed xf86-video-intel, xf86-video-nv and vga-switcheroo after : i decided to install theses packages only after i noticed that it didn’t work properly, whereas with 42.2 it worked out of the box, without any configuration action from me.

With 42.2, that i still use as my every day production tool, the dgpu only turns on when needed, and stays off otherwise.
NB : on 42.2, without the proprietary driver = no bumblebee, only nouveau… And no configuration action from me.
And i don’t understand why it doesn’t work out of the box with 15.0 .

When dgpu does not turn off automatically, laptop is too warm and battery is too short. And i can see what happens because there is a led on the laptop that shows when dgpu is on and another led that shows when the integrated gpu is used instead.
Moreover, the fan noise confirms that something is wrong.

So with 15.0, laptop too warm and battery too short. Why ?

That does not look like the usual “Optimus” laptop, seems more similar to a desktop setup. Maybe there is something in the firmware (BIOS) that can control which GPU is used?
Please provide the result of the following command:

journalctl -b |grep -E 'DSM|nouveau'

Maybe you can add nouveau.runpm=1 to the kernel boot line and see if something changes? (sorry, I’m just guessing; no direct experience with Clevo and some models might have unusual “custom” configurations)

It is a laptop.

I will give the results of your request asap

No doubt about that and if you could write the exact model somebody might find more info about its configuration, which seems more similar to what we can usually find in a desktop.

Here you are :


--root@hostname 11:46:08 /home/chris] journalctl -b |grep -E 'DSM|nouveau'
oct. 15 09:42:28 diesel kernel: ACPI Warning: \_SB.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20170303/nsarguments-95)
oct. 15 09:42:28 diesel kernel: ACPI Warning: \_SB.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20170303/nsarguments-95)
oct. 15 09:42:28 diesel kernel: VGA switcheroo: detected Optimus DSM method \_SB_.PCI0.PEG0.PEGP handle
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: enabling device (0006 -> 0007)
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: NVIDIA GK107 (0e7110a2)
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: bios: version 80.07.1d.00.21
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: fb: 1024 MiB GDDR5
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: VRAM: 1024 MiB
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: GART: 1048576 MiB
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: TMDS table version 2.0
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: DCB version 4.0
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: MM: using COPY for buffer copies
oct. 15 09:42:28 diesel kernel: [drm] Initialized nouveau 1.3.1 20120801 for 0000:01:00.0 on minor 0
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (==) Matched nouveau as autoconfigured driver 2
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) LoadModule: "nouveau"
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) Loading /usr/lib64/xorg/modules/drivers/nouveau_drv.so
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) Module nouveau: vendor="X.Org Foundation"
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) [drm] nouveau interface version: 1.3.1
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) NOUVEAU(G0): [DRI2]   DRI driver: nouveau
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) NOUVEAU(G0): [DRI2]   VDPAU driver: nouveau
oct. 15 11:44:25 diesel.diesel plasmashell[3010]: org.kde.plasmaquick: New Applet  "Notification de nouveau périphérique" with a weight of 0


I tried to insert the " nouveau.runpm=1 " to the kernel boot line … No success.


--root@hostname 12:03:17 /home/chris] journalctl -b |grep -E 'DSM|nouveau'
oct. 15 09:54:17 diesel kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-4.12.14-lp150.12.19-default root=UUID=9cd011c8-fca3-4a97-b587-82af5b0d5d81 resume=/dev/disk/by-uuid/7de93cbd-7d66-40a0-a7ef-928408f3e681 splash=silent quiet showopts nouveau.runpm=1
oct. 15 09:54:17 diesel kernel: Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.12.14-lp150.12.19-default root=UUID=9cd011c8-fca3-4a97-b587-82af5b0d5d81 resume=/dev/disk/by-uuid/7de93cbd-7d66-40a0-a7ef-928408f3e681 splash=silent quiet showopts nouveau.runpm=1
oct. 15 09:54:17 diesel dracut-cmdline[174]: Using kernel command line parameters: resume=UUID=7de93cbd-7d66-40a0-a7ef-928408f3e681 root=UUID=9cd011c8-fca3-4a97-b587-82af5b0d5d81 rootfstype=ext4 rootflags=rw,relatime,data=ordered BOOT_IMAGE=/boot/vmlinuz-4.12.14-lp150.12.19-default root=UUID=9cd011c8-fca3-4a97-b587-82af5b0d5d81 resume=/dev/disk/by-uuid/7de93cbd-7d66-40a0-a7ef-928408f3e681 splash=silent quiet showopts nouveau.runpm=1
oct. 15 09:54:17 diesel kernel: ACPI Warning: \_SB.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20170303/nsarguments-95)
oct. 15 09:54:17 diesel kernel: ACPI Warning: \_SB.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20170303/nsarguments-95)
oct. 15 09:54:17 diesel kernel: VGA switcheroo: detected Optimus DSM method \_SB_.PCI0.PEG0.PEGP handle
oct. 15 09:54:17 diesel kernel: nouveau 0000:01:00.0: enabling device (0006 -> 0007)
oct. 15 09:54:17 diesel kernel: nouveau 0000:01:00.0: NVIDIA GK107 (0e7110a2)
oct. 15 09:54:17 diesel kernel: nouveau 0000:01:00.0: bios: version 80.07.1d.00.21
oct. 15 09:54:17 diesel kernel: nouveau 0000:01:00.0: fb: 1024 MiB GDDR5
oct. 15 09:54:18 diesel kernel: nouveau 0000:01:00.0: DRM: VRAM: 1024 MiB
oct. 15 09:54:18 diesel kernel: nouveau 0000:01:00.0: DRM: GART: 1048576 MiB
oct. 15 09:54:18 diesel kernel: nouveau 0000:01:00.0: DRM: TMDS table version 2.0
oct. 15 09:54:18 diesel kernel: nouveau 0000:01:00.0: DRM: DCB version 4.0
oct. 15 09:54:18 diesel kernel: nouveau 0000:01:00.0: DRM: MM: using COPY for buffer copies
oct. 15 09:54:18 diesel kernel: [drm] Initialized nouveau 1.3.1 20120801 for 0000:01:00.0 on minor 0
oct. 15 11:54:25 diesel.diesel /usr/lib/gdm/gdm-x-session[2812]: Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.12.14-lp150.12.19-default root=UUID=9cd011c8-fca3-4a97-b587-82af5b0d5d81 resume=/dev/disk/by-uuid/7de93cbd-7d66-40a0-a7ef-928408f3e681 splash=silent quiet showopts nouveau.runpm=1
oct. 15 11:54:25 diesel.diesel /usr/lib/gdm/gdm-x-session[2812]: (==) Matched nouveau as autoconfigured driver 2
oct. 15 11:54:25 diesel.diesel /usr/lib/gdm/gdm-x-session[2812]: (II) LoadModule: "nouveau"
oct. 15 11:54:25 diesel.diesel /usr/lib/gdm/gdm-x-session[2812]: (II) Loading /usr/lib64/xorg/modules/drivers/nouveau_drv.so
oct. 15 11:54:25 diesel.diesel /usr/lib/gdm/gdm-x-session[2812]: (II) Module nouveau: vendor="X.Org Foundation"
oct. 15 11:54:25 diesel.diesel /usr/lib/gdm/gdm-x-session[2812]: (II) [drm] nouveau interface version: 1.3.1
oct. 15 11:54:25 diesel.diesel /usr/lib/gdm/gdm-x-session[2812]: (II) NOUVEAU(G0): [DRI2]   DRI driver: nouveau
oct. 15 11:54:25 diesel.diesel /usr/lib/gdm/gdm-x-session[2812]: (II) NOUVEAU(G0): [DRI2]   VDPAU driver: nouveau
oct. 15 11:54:56 diesel.diesel plasmashell[2960]: org.kde.plasmaquick: New Applet  "Notification de nouveau périphérique" with a weight of 0


It’s a problem because i can’t switch off the nvidia card and it burns the battery for nothing

OK thanks, what I understand is that your laptop uses the “Optimus” architecture but unfortunately…

oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: enabling device (0006 → 0007)
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: NVIDIA GK107 (0e7110a2)
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: bios: version 80.07.1d.00.21
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: fb: 1024 MiB GDDR5
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: VRAM: 1024 MiB
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: GART: 1048576 MiB
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: TMDS table version 2.0
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: DCB version 4.0
oct. 15 09:42:28 diesel kernel: nouveau 0000:01:00.0: DRM: MM: using COPY for buffer copies
**oct. 15 09:42:28 diesel kernel: [drm] Initialized nouveau 1.3.1 20120801 for 0000:01:00.0 on minor 0
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (==) Matched nouveau as autoconfigured driver 2
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) LoadModule: “nouveau”
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) Loading /usr/lib64/xorg/modules/drivers/nouveau_drv.so
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) Module nouveau: vendor=“X.Org Foundation”
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) [drm] nouveau interface version: 1.3.1
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) NOUVEAU(G0): [DRI2] DRI driver: nouveau
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) NOUVEAU(G0): [DRI2] VDPAU driver: nouveau
**

… the nouveau driver activates the dGPU and stays that way no matter what instead of putting it to rest unless it is needed (and I don’t understand why at this stage).
Since you appear to still have 42.2 on that box, can you run the same command in 42.2 and look for any differences?
The result of the following under 42.2 might also help, even if I don’t expect differences here:

/sbin/lspci -nnk | grep -EiA3 'vga|3d|display'

Since your firmware appears to include the “Optimus” code, installing bumblebee according to this page:
https://en.opensuse.org/index.php?title=SDB:NVIDIA_Bumblebee&oldid=118653
should work. Since you are using a Kepler card please be aware of the following notice:

Problems with GT600M/GT700M series cards (Kepler)

If you cannot load GPU drivers - while bbswitch being loaded - and get an error like this on a Kepler card:
[INFO]Response: No - error: Could not load GPU driver
[ERROR]Cannot access secondary GPU - error: Could not load GPU driver
Try changing value of ‘load_state’ in “/etc/modprobe.d/50-bbswitch.conf” from 0 to -1

Please also note that with a successfully installed bumblebee you should be able to switch off the dGPU via:

switch state of card manually with bbswitch

check the state of your card:
cat /proc/acpi/bbswitch
to turn your card off, type:
tee /proc/acpi/bbswitch <<<OFF

Please be aware that the instructions to install bumblebee are expected to work on a clean install, so you should revert any other installation or configuration in the video area before trying that.

P.S.: Notice to graphics/Nvidia gurus: your help is welcome, I’m running out of ideas :frowning:

Here is the requested command on 42.2 :


--root@hostname 15:52:18 /home/chris] /sbin/lspci -nnk | grep -EiA3 'vga|3d|display'
00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09)
        Subsystem: CLEVO/KAPOK Computer Device [1558:1550]
        Kernel driver in use: i915
        Kernel modules: i915
--
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GK107M [GeForce GT 650M] [10de:0fd1] (rev a1)
        Subsystem: CLEVO/KAPOK Computer Device [1558:1550]
        Kernel driver in use: nouveau
        Kernel modules: nouveau

Any ideas ?

I understand that installing bbswitch might solve the problem, but does it imply that i install the sometimes very unstable nvidia proprietary driver ?

As expected, no differences here. It might be more interesting to see any differences in the result of:

journalctl -b |grep -E 'DSM|nouveau'

I understand that installing bbswitch might solve the problem, but does it imply that i install the sometimes very unstable nvidia proprietary driver ?

No, as explained in the linked page the proprietary Nvidia driver is optional, bumblebee (and bbswitch) should work with the nouveau driver as well.

Here you are , on 42.2 :



--root@host 13:01:14 /home/chris] journalctl -b |grep -E 'DSM|nouveau'
oct. 18 11:23:16 host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:23:16 host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:23:16 host kernel: VGA switcheroo: detected Optimus DSM method \_SB_.PCI0.PEG0.PEGP handle
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: enabling device (0006 -> 0007)
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: NVIDIA GK107 (0e7110a2)
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: bios: version 80.07.1d.00.21
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: fb: 1024 MiB GDDR5
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: DRM: VRAM: 1024 MiB
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: DRM: GART: 1048576 MiB
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: DRM: TMDS table version 2.0
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: DRM: DCB version 4.0
oct. 18 11:23:16 host kernel: nouveau 0000:01:00.0: DRM: MM: using COPY for buffer copies
oct. 18 11:23:16 host kernel: [drm] Initialized nouveau 1.3.1 20120801 for 0000:01:00.0 on minor 0
oct. 18 11:23:26 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:23:26 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:23:26 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:23:26 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:23:26 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:23:26 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:23:26 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 11:47:58 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 11:47:59 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 11:48:04 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:48:04 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:48:04 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:48:04 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:48:04 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:48:04 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:48:04 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 11:48:17 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 11:48:17 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 11:48:22 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:48:22 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:48:22 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:48:22 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:48:22 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:48:22 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:48:22 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 11:49:51 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 11:49:51 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 11:49:57 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:49:57 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:49:57 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:49:57 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:49:57 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:49:57 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:49:57 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 11:50:34 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 11:50:34 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 11:50:39 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:50:39 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:50:39 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:50:39 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:50:39 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:50:39 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:50:39 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 11:51:13 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 11:51:13 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 11:51:18 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:51:18 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:51:18 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:51:18 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:51:18 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:51:18 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:51:18 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 11:52:10 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 11:52:10 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 11:52:15 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:52:15 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:52:15 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:52:15 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:52:15 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:52:15 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:52:15 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 11:54:16 host.host kernel:  iwlwifi aesni_intel rtsx_pci_ms aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd memstick r8169 mii cfg80211 rfkill joydev i2c_i801 lpc_ich mei_me soundcore mei battery tpm_infineon pcspkr shpchp thermal fjes ac processor ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod uas usb_storage hid_generic usbhid rtsx_pci_sdmmc mmc_core ahci libahci libata nouveau mxm_wmi xhci_pci i915 ttm xhci_hcd ehci_pci ehci_hcd usbcore serio_raw usb_common i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops rtsx_pci mfd_core drm wmi video button sg scsi_mod autofs4                                                          
oct. 18 11:56:01 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 11:56:01 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 11:56:06 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:56:06 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:56:06 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:56:06 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:56:06 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:56:06 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:56:06 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 11:57:21 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 11:57:21 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 11:57:26 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:57:26 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 11:57:26 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 11:57:26 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 11:57:26 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 11:57:26 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 11:57:26 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 12:44:35 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 12:44:36 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 12:44:41 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 12:44:41 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 12:44:41 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 12:44:41 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 12:44:41 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 12:44:41 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 12:44:41 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 12:46:28 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 12:46:28 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 12:46:33 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 12:46:33 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 12:46:33 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 12:46:33 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 12:46:33 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 12:46:33 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 12:46:33 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 12:48:09 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 12:48:09 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 12:48:14 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 12:48:14 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 12:48:14 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 12:48:14 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 12:48:14 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 12:48:14 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 12:48:14 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
oct. 18 12:48:30 host.host kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
oct. 18 12:48:31 host.host kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
oct. 18 12:48:36 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 12:48:36 host.host kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
oct. 18 12:48:36 host.host kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
oct. 18 12:48:36 host.host kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
oct. 18 12:48:36 host.host kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
oct. 18 12:48:36 host.host kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
oct. 18 12:48:36 host.host kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...

OK, here is (in BOLD) where the nouveau kernel module switches off the dGPU after failing to deal with the “Optimus” _DSM method on 42.2.
Ironically an updated ACPI on Leap 15 seems to be able to deal with that _DSM method and so uses the dGPU whenever possible…
I never witnessed such a behaviour on my “standard Optimus” machines, so I’m running out of ideas here.

But from an earlier post of yours I read that apparently you are using GDM (the Gnome Display Manager) with a Plasma desktop environment:

oct. 15 09:42:28 diesel kernel: [drm] Initialized nouveau 1.3.1 20120801 for 0000:01:00.0 on minor 0
oct. 15 11:44:14 diesel.diesel /usr/lib/**gdm/gdm-x-session**[2856]: (==) Matched nouveau as autoconfigured driver 2
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) LoadModule: "nouveau"
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) Loading /usr/lib64/xorg/modules/drivers/nouveau_drv.so
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) Module nouveau: vendor="X.Org Foundation"
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) [drm] nouveau interface version: 1.3.1
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) NOUVEAU(G0): [DRI2]   DRI driver: nouveau
oct. 15 11:44:14 diesel.diesel /usr/lib/gdm/gdm-x-session[2856]: (II) NOUVEAU(G0): [DRI2]   VDPAU driver: nouveau
oct. 15 11:44:25 diesel.diesel **plasmashell[3010]**: org.kde.plasmaquick: New Applet  "Notification de nouveau périphérique" with a weight of 0

I really don’t know if this “non default” setup has anything to do with your problem, but if I were to use KDE/Plasma I would use sddm as display manager, or at least give it a shot.
By default GDM uses Wayland and that might have a role in keeping your dGPU alive; if you definitely need GDM there is a config to disable Wayland though:
just uncomment the line reading “WaylandEnable=false” in /etc/gdm/custom.conf

Thank you OrsoBruno for your very accurate observations and explanations.
But, regarding gdm/ssdm, it doesn’t change anything. The same bad behavior is observed with sddm.

( I switched to gdm because sddm has bugs regarding multiple user graphic sessions : https://forums.opensuse.org/showthread.php/533047-unable-to-have-two-graphical-user-workspace-SDDM-unable-to-switch-user)

It is quite strange that an acpi update triggers regression .