Re: [regression, bisected, pci/iommu] Bug 216865 - Black screen when amdgpu started during 6.2-rc1 boot with AMD IOMMU enabled

[Matt Fagnani]

I booted 6.2-rc2 + the patch four times with early kdump enabled and 
panicked the kernel. There weren't any kdump or dmesg files saved to 
/var/crash though. Nothing showed up in the journal from boots where the 
problem happened. The amdgpu crash happened before systemd-journald 
started from what I could tell. I tried to rebuild 
/boot/initramfs-6.2.0-rc2+kdump.img with amd_iommu=off added to the 
kernel command line with dracut, but an error that the kdumpbase module 
couldn't be found was shown. I read that a different dump capture kernel 
could be used with kdump, but I haven't figured out how to use that with 
early kdump yet. If anyone has ideas how to get the kdump and dmesg log, 
let me know. Thanks.