arm/150581: Unknown error generates IRQ address decoding error

[Johny Mattsson]

Hi Tyler,

The issue could be the same that I'm having on my PogoPlug (stripped down
version of the Sheevaplug essentially). I don't have a serial console on it,
so I haven't been able to get any actual error messages, but I do experience
the same hard hang when I have heavy USB I/O. I'm still working on resolving
this issue properly, but I have found a work-around. If rolling back those
patches didn't fix the problem for you, try limiting the amount of RAM the
kernel sees down to 128MiB. For me, going from the actual 256MiB down to
128MiB prevents the I/O lock-up and I have a stable system (I can in fact
push it up to 131MiB, but above that it's bad news).

To limit the RAM, open /usr/src/sys/boot/fdt/dts/sheevaplug.dts, find the
"memory" entry and reduce it to 0x08000000, then rebuild your kernel.

I'd be very interested in hearing whether this fixes your issue, as it's
been quite frustrating to troubleshoot this without seeing what goes on the
console when the hang occurs!

Regards,
/Johny