Public bug reported: I'm on a Ryzen 1800X and Biostar B350GT5 on bionic kubuntu.
Lots of AMD-Vi logged events and I get irq crashes or acpi hangups with a normal boot. How I it to work is to disable IOMMU in the BIOS and add "iommu=soft" to the kernel booting options in grub. linux can then detect everything properly (all cores) and I've had zero crashes. The only issue is that it's using software IOMMU. Alternatively it boots with the kernel option "acpi=off" but only detects a single core/thread. I attached a kernel log. I believe(d) this might be related to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1671360 and https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1690085 ** Affects: linux (Ubuntu) Importance: Undecided Status: Incomplete ** Tags: kernel-bug ryzen ** Attachment added: "kernlog" https://bugs.launchpad.net/bugs/1747463/+attachment/5049263/+files/kernlog -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1747463 Title: kernel crashes unless IOMMU is disabled on Ryzen 1800X To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1747463/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
