Does drm/dri currently work on PPC? (SUCCESS!)

[Justin Hibbits]

On Fri, Oct 26, 2012 at 12:55 AM, matt <sendtomatt at gmail.com> wrote:

>
> > It was working without DRM "out-of-the-box". Of course I've made a mess
> > trying different versions of both Xorg and the radeon driver. I'm in the
> > process of getting back to the working config so I can be sure any test
> > changes work/don't work.
> >
> > OpenBSD's mpi@ apparently did a lot recently over there getting DRM to
> > work on the G4 mini. We already had about half of the commits I see at
> > freshbsd, in one way or another...Our rmb/wmb() I think has had PPC
> > barriers since earlier this year? He did #define __BIG_ENDIAN, which
> > apparently was a big deal for the drm code (it's ifdef'd in a couple
> > places), not sure if we are already doing that.
> > If someone has a G4 radeon mini they could test to see if drm works for
> > them or not, to rule out AGP issues (I guess they are PCI?).
> >
> > I'm not sure how the OpenBSD attachment process works vs ours, some of
> > the other commits of note were related to passing the BAR and memory
> > regions from the vgapci to drm. When I kldload drm after compiling it,
> > it doesn't do anything...but if I kldload radeon.ko, it recognizes agp
> > memory and being related to vgapci at the correct pci address...I'm not
> > sure if we "are there" or not. I also didn't have DRM on OpenBSD either.
> >
> > I think if radeon had drm on *any* big-endian platform it should rule
> > out endian issues in drm or radeon. Not sure if this is the case, I
> > guess macppc would be the most likely.
> >
> > Matt
> So I removed WITH_NEW_XORG, deinstalled a ton of ports, and reinstalled
> Xorg. I rebuild drm with __BIG_ENDIAN defined (not sure if this
> matters). I previously put a lot of WERROR= and NO_WERROR= into various
> drm makefiles to get gcc to shut up about unused return values. X
> -configure worked, and the xorg log indicates the drm device was
> successfully opened and I have drm on PPC.
> mesa-demos is marked broken for PPC, haven't tried glxinfo or glxgears yet.
>
> The good news is it works!
> The bad news:
> -Cannot switch back to syscons, screen gets corrupted then the system
> hard locks
> -WITH_NEW_XORG breaks it somehow
>
> Thanks to mpi at openbsd.org, Justin & Nathan!
>
> Matt
>

That's fantastic!  If I'm able to get my current project done (PMU
sleep/speed change on PowerBook) I'll definitely give that a shot this
weekend.

One thing that may help with switching back to syscons is, NetBSD has a
radeonfb driver for console framebuffer.Earlier in the week I briefly
looked at that, and it may not be too difficult to port it to FreeBSD and
integrate with syscons.  Only major hurdle for that would be dealing with
ofwfb as well.  Just some more tinkering :)

Excellent news!

- Justin