Richard,
Thanks for the additional info. I'm
assuming you are using the stock kernel that comes with Jessie? If so,
you'll need to either a) re-build your own kernel that that uses 4K page
sizes and has MSI interrupts disabled b) download the kernel image
provided by Peter Saisanas that has this done for you already . More
information on these bugs can be found here:
https://lists.debian.org/debian-powerpc/2015/06/msg00054.html.
A bug report has been filed for both issues.
Bug#790690: linux-image-3.16.0-4-powerpc64: powerpc64 & 64Kb kernel pagesize not working with nouveau
Bug#790694: linux-image-3.16.0-4-powerpc64: nouveau driver and msi interrupts
The
only other way "around" this with the stock kernel is to disabled
acceleration on the card by passing in nouveau.noaccel=1 at the yaboot
prompt.
Thanks,
Brock