0

There is a problem with my display ouput.

The Asus ZenScreen monitor cannot detect a signal after switching off and on again. I will have to hibernate the machine before the display can work again.

Apparently, the system is unable to detect the xrandr connection type for my display:

xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080
default connected primary 1920x1080+0+0 0mm x 0mm
   1920x1080     77.00* 
  1920x1080_60.00 (0x55a) 173.000MHz -HSync +VSync
        h: width  1920 start 2048 end 2248 total 2576 skew    0 clock  67.16KHz
        v: height 1080 start 1083 end 1088 total 1120           clock  59.96Hz

possibly due to a lack of driver for my graphics card:

inxi -G
Graphics:
  Device-1: Intel UHD Graphics driver: N/A 
  Display: x11 server: X.Org 1.20.11 driver: fbdev 
  unloaded: modesetting,vesa resolution: 1920x1080~77Hz 
  OpenGL: renderer: llvmpipe (LLVM 12.0.0 256 bits) 
  v: 4.5 Mesa 21.0.3

It says here that a kernel upgrade is needed,

intel_gpu_top
Failed to detect engines! (No such file or directory)
(Kernel 4.16 or newer is required for i915 PMU support.)

But my kernel version is clearly newer than the 4.16 requirement.

uname -r
5.11.0-27-generic

Assuming the driver is already installed with the kernel, though I can select intel as my driver,

prime-select query
intel

it is apparent the Intel UHD Graphics card cannot detect any compatible driver in the kernel. (No Kernel driver in use in the output below.)

lspci -k
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics (rev 02)
    DeviceName:  GPU
    Subsystem: Intel Corporation UHD Graphics
    Kernel modules: i915

Can someone diagnose what's the issue over here?

The xrandr command had been working properly with the same setup before.

Sati
  • 109

1 Answers1

-1

I've found out what's wrong. Here's what I did:

sudo nvim /etc/default/grub

Change this line:

GRUB_CMDLINE_LINUX="nomodeset"

to this:

GRUB_CMDLINE_LINUX=""

Then:

sudo update-grub

And the display is working properly again.

inxi -G
Graphics:  Device-1: Intel UHD Graphics driver: i915 v: kernel 
           Display: x11 server: X.Org 1.20.11 driver: fbdev unloaded: modesetting,vesa 
           resolution: 1920x1080~60Hz 
           OpenGL: renderer: Mesa Intel UHD Graphics (CML GT2) v: 4.6 Mesa 21.0.3 

lspci -k
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics (rev 02)
    DeviceName:  GPU
    Subsystem: Intel Corporation UHD Graphics
    Kernel driver in use: i915
    Kernel modules: i915
Sati
  • 109
  • So you just undid what you you did before that caused the problem? This is likely a misunderstanding of what nomodeset does and its purpose as a temporary workaround to have video until the user installs some required proprietary drivers - currently only applicable to Nvidia, but you have Intel??? -, not a "solution" for anything. It shoud be noted that this kernel parameter doesn't appear ex nihilo, it is always added by users. – ChanganAuto Aug 20 '21 at 14:00
  • I modified the settings to nomodeset before to solve the problem of not reaching the login screen upon reboot. I wasn't aware of any side-effects of this setting at that time. – Sati Aug 20 '21 at 14:12
  • Things seem to be working fine after the reset. @ChanganAuto, I would appreciate a proper solution or an explanation for what nomodeset does to cause the problem above. – Sati Aug 20 '21 at 14:16
  • 1
    nomodeset (No Mode Set) is used to override any graphics driver thus forcing a fallback standard VESA graphics mode, typically low resolution, that should be supported by any graphics subsystem in any circumstance. As explained above it's or was typically used when a brand new Nvidia chipset has no proper support by the open-source alternative nouveau driver and the default in Ubuntu. However, since a few releases ago users have the option to automatically install Nvidia proprietary driver thus not requiring the nomodeset workaround. – ChanganAuto Aug 20 '21 at 14:23
  • I was merely following the instructions over here to solve the blank screen problem. – Sati Aug 20 '21 at 14:26