Re: Recent commits reject RPi4B booting: pcib0 vs. pcib1 "rman_manage_region: <pcib1 memory window> request" leads to panic

On Mon, Feb 12, 2024 at 09:36:46AM -0800, John Baldwin wrote:
> Without a stack trace it is pretty much impossible to debug a panic like this.
> Do you have KDB_TRACE enabled in your kernel config?  I'm also not sure how the
> PCI changes can result in a panic post-boot.  If you were going to have problems
> they would be during device attach, not after you are booted and running X.
> 
> Short of a stack trace, you can at least use lldb or gdb to lookup the source
> line associated with the faulting instruction pointer (as long as it isn't in
> a kernel module), e.g. for gdb you would use 'gdb /boot/kernel/kernel' and then
> 'l *<instruction pointer address>', e.g. from above: 'l *0xffffffff80acb962'

  I know on my RPI4 where I saw that, my USB keyboard was dead at that point
and I couldn't get a trace or continue along to get the crashdump.