Distribution (run cat /etc/os-release):
Pop!_OS 21.04.

Related Application and/or Package Version (run apt policy $PACKAGE NAME):
Linux kernel.

Issue/Bug Description:
Show-stopping graphic glitches with pinkish horizontal lines blurring the bottom half of the screen, as if this part of the screen could not be refreshed properly. The system is not usable in that state.

Relevant error log: pop-os kernel:

pop-os kernel: i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun

I was not able to extract more specific logs.

Steps to reproduce (if you know):
Boot the machine. Every hour or so, the bug occurs, making the machine unusable expect by rebooting.

Expected behavior:
No issue at all on 5.13.

Other Notes:

lspci
> 00:02.0 VGA compatible controller: Intel Corporation HD Graphics 530 (rev 06)

I also have an NVIDIA GPU but not using it (nouveau.modeset=1 and no proprietary driver used either).