Comment 331 for bug 1776563

Yes, I tried:

"text ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2 radeon.modeset=0 amdgpu.runpm=0"

"text ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2 clocksource=hpet iommu=on amd_iommu=on amdgpu.dc=1"

"idle=nomwait iommu=pt amd_iommu=on rcu_nocbs=0-7 pcie-aspm=off ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2 amdgpu.dc=1"

...

Tried 5.0 mainline kernel also, same result, suspend works, but graphics is slow and bumps cpu on system monitor to 10-50% just for moving windows in gnome, unlike pci=noacpi when cpu never goes anywhere near 10% for usual DE manipulations.

Also if run with ivrs_ioapic params, switcheroo service fails with message "switcheroo-cont[3648]: switcheroo-control could not query vga_switcheroo status: Operation not permitted". This might be interaction with this secure boot bug: https://bugs.launchpad.net/ubuntu/+source/switcheroo-control/+bug/1768988

BTW if I disable secure boot it doesn't boot at all with ivrs_ioapic params set.