lightdm Linux login screen graphics glitch?

[Ultraforce]

I started setting up Linux to dual boot for an additional coding environment earlier this week and have been doing tweaks such as changing the login screen finding a way so that I don't use the default Dell boot loading screen that's all blue and make pop!_OS feel a bit more like Windows with KDE but have noticed even after fixing the stuff where something would crash I get these weird graphical glitches as seen in the first image either when restarting the fcomputer or after choosing to boot up into pop. Does anyone have any ideas as to possible causes and fixes?

Thank you for your time,

Ultraforce.

[cretsiah]

Try the " The Advanced options for POPOS " and select recovery...

 

if this gives you a clean screen

 

check what graphics driver (if any ) you have installed and also the kernel version

 

then post here with your results + your hardware info .....

[Ultraforce]

19 hours ago, cretsiah said:

Try the " The Advanced options for POPOS " and select recovery...

 

if this gives you a clean screen

 

check what graphics driver (if any ) you have installed and also the kernel version

 

then post here with your results + your hardware info .....

The first time after selecting recovery I also selected the update grub and repair files and that time it was clean though after restarting, switching to Windows and back again even going to recovery mode did not fix the issue. Given the visual aspect of the glitches I think it might have something to do with both my C:Drive containing Windows and the Pop!_OS boot drives being on the same physical device.

The kernel version I have is Linux 5.15.8-76051508-generic x86_64

The NVIDIA driver version I have is 470.86

 

My hardware info is as follows

• OS - Windows 10 / Pop!_OS 21.10
• x86-64 ?
• What OS was originaly installed on the system? Windows 10
• Is the OS an OEM version (came pre-installed on system) or full retail version (YOU purchased it from a retailer)? It was the OEM version but I refactored the C drive and I think I removed some of the OEM stuff.
• Age of system (hardware) The system was manufactured march 2018.
• Age of OS installation - have you re-installed the OS? Yes
• CPU model Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
• Video Card model NVIDIA GeForce GTX 1070
• MotherBoard - Dell Inc.0DF42J .98V69N2.CNPE10081400S4.
• Power Supply - brand & wattage (if laptop, skip this) don't know
• System Manufacturer:  Dell
• Exact model number : The Express Service Code is 20127130958 and I will check the exact model number when I switch back to Windows.
• Desktop
• Monitors : Asus VZ27V, Lenovo LEN C32q-20. The Asus is using displayport and the lenovo is using HDMI.

 

[18358414]

I get a similar issue sometimes on Arch Linux with my 750TI, but usually only when I reboot from Windows back to Linux.  For a brief moment while the X server is starting up some icons and visual elements from my last Windows session are displayed on screen because I guess NVidia doesn't care to clear out the video memory when you reboot your machine.  It freaked me out the first time it happened to me, because I started up Linux and right before the login screen rendered a distorted picture of the Terminator jumped up on my screen.  It's been off-and-on for about 4 years now I guess.  I strongly suspect you are having the same issue because your image #1 appears to show Windows UI elements that are rendered and not stored as actual files. 

 

If you're getting coherent images when you do a fresh boot (i.e. going from completely shut down to completely powered on), something weird is happening; if you get coherent images when you reboot, it's probably just whatever was stored in video ram from your last session.  There shouldn't be a way for Linux to coherently read files from a Windows partition until it's been mounted, and even then Linux devs are very picky about avoiding random filesystem reads. 

 

I am not currently aware of any method to wipe video memory or re-initialize it with all zeros aside from writing a custom program that just stuffs your video ram with zeros.

[Ultraforce]

4 minutes ago, Yuri Fury said:

I get a similar issue sometimes on Arch Linux with my 750TI, but usually only when I reboot from Windows back to Linux.  For a brief moment while the X server is starting up some icons and visual elements from my last Windows session are displayed on screen because I guess NVidia doesn't care to clear out the video memory when you reboot your machine.  It freaked me out the first time it happened to me, because I started up Linux and right before the login screen rendered a distorted picture of the Terminator jumped up on my screen.  It's been off-and-on for about 4 years now I guess.  I strongly suspect you are having the same issue because your image #1 appears to show Windows UI elements that are rendered and not stored as actual files. 

 

If you're getting coherent images when you do a fresh boot (i.e. going from completely shut down to completely powered on), something weird is happening; if you get coherent images when you reboot, it's probably just whatever was stored in video ram from your last session.  There shouldn't be a way for Linux to coherently read files from a Windows partition until it's been mounted, and even then Linux devs are very picky about avoiding random filesystem reads. 

 

I am not currently aware of any method to wipe video memory or re-initialize it with all zeros aside from writing a custom program that just stuffs your video ram with zeros.

I don't think I've tested it in a completely fresh boot, but yeah my guess is what you described, it seems like it probably isn't too big of a deal since the graphical glitch doesn't occur when I'm actually using it and only when I restart one to another.