My laptop with Ubuntu 20.04 totally freezes at random times and audio loops what was playing the last 1 or 2 seconds before freezing. I can't switch to another tty and Alt + SysRq + REISUB does absolutely nothing. System logs don't show anything strange, but I have found other users with a similar problem on other distros and the freezes should be related to Intel CPUs (My laptop has an Intel i3-5010u). I don't think this is related but I've been using dwm, and I don't think this has happened to me while i was using Gnome. The only thing that seems wrong is that this error: [ 3515.974328] iwlwifi 0000:03:00.0: Microcode SW error detected. Restarting 0x2000000. keeps repeating forever.
EDIT: Disabling iommu seems to resolve this, no freezes since yesterday. I'll update this post in a few days if no freezes occur.
