no image on monitor on laptop with two graphics card (onboard intel+nvidia rtx3050) if run nvidia only

[hetman]

i have laptop (Vendor:MSI / Model:Katana GF76 11UC) with two graphics card (onboard intel+nvidia rtx3050)

I didn't like how intel (i915) works (flickering problem has not yet been overcome) so I decided to try using nvidia only.

I spent a long time dealing with the "xorg" settings in order to run "x" on nvidia only:
* disable the i915 driver with kernel settings: `modprobe.blacklist=i915 i915.modeset=0`
* rename /usr/share/X11/xorg.conf.d/20-intel.conf to *.bak
* then modify /usr/share/X11/xorg.conf.d/10-nvidia.conf (set Identifier "Card0" )

after starting startx on the screen, the image freezes when switching to tty2 and back to tty1, the server does not render anything, and if you open `top` in tty2, you can see:
```
MiB Mem : 31808,1 total, 24998,2 free, 5471,6 used, 1338,3 buff/cache
MiB Swap: 954,0 total, 954,0 free, 0,0 used. 25914,7 avail Mem

    PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
   2547 root 20 0 2880328 156160 86076 R 100,3 0,5 6:19.96 kwin_x11
   3033 hetman 20 0 3052116 350728 186196 S 1,0 1,1 0:06.43 firefox
   3314 hetman 20 0 2477080 140688 93056 S 1,0 0,4 0:01.23 Isolated Web Co
    306 root 20 0 0 0 0 I 0,3 0,0 0:00.36 kworker/6:2-events
    776 message+ 20 0 9044 6032 3828 S 0,3 0,0 0:01.62 dbus-daemon
    801 root 20 0 16852 7828 6892 S 0,3 0,0 0:00.17 systemd-logind
   2967 hetman 20 0 5771360 4,4g 124548 S 0,3 14,1 2:04.60 plasmashell
   3000 hetman 20 0 340504 63760 50732 S 0,3 0,2 0:00.37 kwalletd5
   3207 hetman 20 0 2427008 110324 89080 S 0,3 0,3 0:00.30 Privileged Cont
   3607 root 20 0 0 0 0 I 0,3 0,0 0:00.03 kworker/u24:2-events_power_efficient
```
 nvidia-smi
```
hetman@katana-lin:/mnt/giga/xorg_nvidia$ cat mvidia-smi.log
Mon Mar 7 23:03:53 2022
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 510.47.03 Driver Version: 510.47.03 CUDA Version: 11.6 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|===============================+======================+======================|
| 0 NVIDIA GeForce ... Off | 00000000:01:00.0 Off | N/A |
| N/A 41C P8 N/A / N/A | 132MiB / 4096MiB | 0% Default |
| | | N/A |
+-------------------------------+----------------------+----------------------+

+-----------------------------------------------------------------------------+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=============================================================================|
| 0 N/A N/A 2847 G /usr/lib/xorg/Xorg 12MiB |
| 0 N/A N/A 2967 G /usr/bin/plasmashell 8MiB |
| 0 N/A N/A 3033 G /usr/lib/firefox/firefox 85MiB |
| 0 N/A N/A 4436 G ...bexec/kscreenlocker_greet 12MiB |
+-----------------------------------------------------------------------------+
```
Thus, I stated that the X's started up and are working, but the image is not displayed.

if return
modprobe i915.modeset=1
/usr/share/X11/xorg.conf.d/20-intel.conf
/usr/share/X11/xorg.conf.d/10-nvidia.conf

- otherwise the output always goes through only intel (i915)
nvidia not uses even if use `prime-select nvidia` - this option ignoring

-----
Description: Ubuntu 20.04.4 LTS
Release: 20.04

nvidia-driver-510:
  Installed: 510.47.03-0ubuntu0.20.04.1
  Candidate: 510.47.03-0ubuntu0.20.04.1
  Version table:
 *** 510.47.03-0ubuntu0.20.04.1 500
        500 http://by.archive.ubuntu.com/ubuntu focal-updates/restricted amd64 Packages
        500 http://security.ubuntu.com/ubuntu focal-security/restricted amd64 Packages
        100 /var/lib/dpkg/status
hetman@katana-lin:/mnt/giga/xorg_

hetman@katana-lin:~$ hwinfo --gfxcard
16: PCI 100.0: 0302 3D controller
  [Created at pci.386]
  Unique ID: VCu0.AC6K6Gkky5B
  Parent ID: vSkL.7WoufefUDA8
  SysFS ID: /devices/pci0000:00/0000:00:01.0/0000:01:00.0
  SysFS BusID: 0000:01:00.0
  Hardware Class: graphics card
  Model: "nVidia 3D controller"
  Vendor: pci 0x10de "nVidia Corporation"
  Device: pci 0x25a2
  SubVendor: pci 0x1462 "Micro-Star International Co., Ltd. [MSI]"
  SubDevice: pci 0x12eb
  Revision: 0xa1
  Driver: "nvidia"
  Driver Modules: "nvidia"
  Memory Range: 0x81000000-0x81ffffff (rw,non-prefetchable)
  Memory Range: 0x6000000000-0x60ffffffff (ro,non-prefetchable)
  Memory Range: 0x6100000000-0x6101ffffff (ro,non-prefetchable)
  I/O Ports: 0x4000-0x407f (rw)
  Memory Range: 0x82000000-0x8207ffff (ro,non-prefetchable,disabled)
  IRQ: 139 (920082 events)
  Module Alias: "pci:v000010DEd000025A2sv00001462sd000012EBbc03sc02i00"
  Driver Info #0:
    Driver Status: nvidiafb is not active
    Driver Activation Cmd: "modprobe nvidiafb"
  Driver Info #1:
    Driver Status: nouveau is not active
    Driver Activation Cmd: "modprobe nouveau"
  Driver Info #2:
    Driver Status: nvidia_drm is active
    Driver Activation Cmd: "modprobe nvidia_drm"
  Driver Info #3:
    Driver Status: nvidia is active
    Driver Activation Cmd: "modprobe nvidia"
  Config Status: cfg=new, avail=yes, need=no, active=unknown
  Attached to: #12 (PCI bridge)

24: PCI 02.0: 0300 VGA compatible controller (VGA)
  [Created at pci.386]
  Unique ID: _Znp.3c68NaQru6A
  SysFS ID: /devices/pci0000:00/0000:00:02.0
  SysFS BusID: 0000:00:02.0
  Hardware Class: graphics card
  Device Name: "Onboard - Video"
  Model: "Intel VGA compatible controller"
  Vendor: pci 0x8086 "Intel Corporation"
  Device: pci 0x9a68
  SubVendor: pci 0x1462 "Micro-Star International Co., Ltd. [MSI]"
  SubDevice: pci 0x12eb
  Revision: 0x01
  Driver: "i915"
  Driver Modules: "i915"
  Memory Range: 0x6102000000-0x6102ffffff (rw,non-prefetchable)
  Memory Range: 0x4000000000-0x400fffffff (ro,non-prefetchable)
  I/O Ports: 0x5000-0x503f (rw)
  Memory Range: 0x000c0000-0x000dffff (rw,non-prefetchable,disabled)
  IRQ: 157 (10681 events)
  Module Alias: "pci:v00008086d00009A68sv00001462sd000012EBbc03sc00i00"
  Driver Info #0:
    Driver Status: i915 is active
    Driver Activation Cmd: "modprobe i915"
  Config Status: cfg=new, avail=yes, need=no, active=unknown

Primary display adapter: #24

[Daniel van Vugt (vanvugt)]

Thanks for the bug report.

This is probably not a bug at all since most laptops only have the Intel GPU wired to the laptop screen. So to disable i915 is to mostly disable the laptop screen.

I suggest instead of pursuing this bug we should fix the i915 "flickering problem". Please re-enable i915 and then while the flickering problem is happening open a new bug by running:

  ubuntu-bug xorg

Although xorg is almost always the wrong package, it's a good place to start when reporting graphics bugs.

[hetman (hetman)]

I do not exclude such a possibility, but I suppose since I definitely have 2 video cards, then there are problems 2. I opened a separate topic on i915: # 1964090.

But I would like to make sure that what you say is true. regarding the dependence of the display on intel.

I may not have enough information, but it seems to me that I can definitely turn off the 915 driver and at the same time I can continue to work in the tty`s console.

although there may be information confirming your words. so for example when X starts on i915 then in the logs there is

[ 839.172] (--) intel(0): Output eDP1 using initial mode 1920x1080 on pipe 0
[ 839.172] (--) intel(0): Output HDMI1 using initial mode 1920x1080 on pipe 1
..
[ 840.294] (II) intel(0): Modeline "1920x1080"x0.0 368.14 1920 1968 2000 2102 1080 1090 1095 1216 -hsync -vsync (175.1 kHz eP)
[ 840.294] (II) intel(0): Modeline "1920x1080"x0.0 153.40 1920 1968 2000 2102 1080 1090 1095 1216 -hsync -vsync (73.0 kHz e)

but when running without i915, I did not find similar lines for nvidia but have a
[ 1327.768] (WW) NVIDIA(0): Unable to get display device for DPI computation.
it maybe:
1. I made a mistake with the settings xorg
2. software bug
3. your option is that it won’t work at all without intel

[Daniel van Vugt (vanvugt)]

Yes the screen will still light up if you disable the i915 kernel driver. But you're essentially using BIOS graphics then. You would lose:

  * High resolution
  * Hardware acceleration
  * Multi-GPU support

Basically graphical desktops won't work anymore, so you shouldn't disable the i915 kernel driver.

Separately, as mentioned in bug 1964090 the old 'intel' Xorg driver is buggy and should be removed:

  sudo apt remove xserver-xorg-video-intel