Hello Thank you for reading this topic and trying to help me
Ubuntu Version:
24.04.4 LTS, 26.04 LTS (one partition for each version)
Desktop Environment:GNOME
Problem Description:
The screen sometimes freezes indefinitely, probably around 10-15 times a week (I use the system at least 5 hours every day).
When it happens, I use the power button to force the shutdown, then I boot the system again. Usually, the screen freezes again after 1 to 5 minutes so I reboot again. And again. And again. Maybe 4-5 times in total before the screen stops freezing.
Note that processes continue normally when the screen freezes; for instance, if music was playing, it continues to play.
The problem happened on Ubuntu 24 so I hoped installing Ubuntu 26 with a fresh install would fix the issue but it unfortunately doesn’t.
Note that the PC isn’t busy when the screen freezes since I’m usually just writing text or browsing the web.
graphics drivers : for Ubuntu 26, during the installation, I checked the checkbox saying “Install third-party drivers for graphic and Wi-fi hardware”. It seems to be NVIDIA driver version 595.58.03 according the app “NVIDIA Xserver settings”.
What I’ve Tried:
changing drivers (on Ubuntu 24, but not on Ubuntu 26 since it should be the right drivers on it)
I forget to say it in the post but I’ve ran the “memtest” option on the GRUB menu but I stopped it after it said “PASS” (it continued after that, i don’t know why). Is it what you’re talking about? I can definitely run that test again.
EDIT: I’ve just done two additional passes of memtest (in addition to the one I did in the past) and there are still no error. I guess this means the RAM is probably okay?
I suspect your (closed source proprietary) nVidia GPU driver though I can not say for sure.
The way to test this is to test with a different nVidia driver and the open source one and see if the problem persists.
I don’t say that this will lead to the answer but it is one of the usual suspects to rule out
Try adding amdgpu.dcdebugmask=0x12 to boot options.
I had this issue on Arch, although currently on Kubuntu 26.04 this has not (at least yet) surfaced. This solved issues for me then. This happens on some integrated AMD cards (I have same as you), but it’s not that much known/discussed online.
Thank you your reply I’ve just updated the BIOS via my Windows partition (I have a 3rd partition where I have Windows). If the freeze doesn’t happen within the next few days, I’ll mark your answer as the solution
Thank you to the other two respondents, too! I will come back and try your solutions if the freeze happens again in the next few days.
The problem persists, so I’ve just applied your solution: I’ve wrote GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash amdgpu.dcdebugmask=0x12” in /etc/default/grub. I will come back soon to inform you all if this solution fixed the problem!
Have you tried forcing performance mode in prime profiles ? This can be related to power management with Nvidia driver, i also have a laptop with Nvidia GPU and was experiencing freezes when i wake laptop from sleep or when waking the screen, then i have to resort to forced shutdown. I changed prime profile to performance mode and it fixed the issue
Thank you for reading this topic and trying to help me 
