https://bugs.freedesktop.org/show_bug.cgi?id=95017

--- Comment #9 from Ilia Mirkin imirkin@alum.mit.edu --- (In reply to Mathieu Malaterre from comment #8)

(In reply to Ilia Mirkin from comment #7)

...

FWIW on nouveau we just default agpmode=0 in a #ifdef __powerpc__. Perhaps the same thing can work for radeon.

Well radeon_agpmode is already set to 0 already[*]. My patch force to PCI(-1) when user did not specify any value.

[*]https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/radeon/ radeon_drv.c#L173

Oh, the logic is flipped from nouveau... on nouveau, -1 == autodetect and 0 == no agp. So in your case, just set it to -1 instead of 0 for powerpc. i.e.

#ifdef __powerpc__ int radeon_agpmode = -1; #else int radeon_agpmode = 0; #endif

or something similar.