Ben,

Are these what you are looking for? I can dump the entire journalctl log if you need it.

Mathieu,

In Debian I looked in /etc/modules, /etc/modprobe.d/ , and /usr/share/X11/xorg.conf.d/ to see where I can find what is forcing the GPU into PCI mode and I have found nothing.

Here are some more updates with Lubuntu 16.10

1. Video playback with mpv renders in opengl with the GPU not in PCI mode

2. compton freezes the DE when I use opengl as the backend but works with xrender

Regards,

Herminio

On Mon, Sep 19, 2016 at 3:38 AM, Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:

On Mon, 2016-09-19 at 02:13 -0700, Herminio Hernandez, Jr. wrote:
>
> I noticed the GPU was set to PCI mode however I did not set
> radeon.agpmode=-1 in yaboot. I then installed Lubuntu 16.10 along
> side Debian. I noticed that GPU was working and it was not set to
> force PCI mode. Has there been a change to kernel in Debian to force
> this by default? If so it looks like it is breaking on certain G5
> machines. I am attaching bothe dmesg files for review.
>
> Thanks and sorry for the previous garbled email.

Hrm... this is odd. I would expect PCI mode to work and AGP to be
busted to be honest. Can you provide the complete log ? I wonder
if it's trying to enable the PCIe bypass high aperture and hits the
Radeon address limit...

Ben.