[GEM-dev] Gem/Mesa-DRI incompatibility [Was: THANK YOU ...]

[Frank Barknecht]

Hallo,
B. Bogart hat gesagt: // B. Bogart wrote:

> I have no idea also, so It would be very nice if Gem worked with DRI and
> not only binary blobs, if there is something missing from DRI that keeps
> gem from working those folks should hear about it. I still don't get why
> all other openGL apps work, even complex pixelshading stuff with
> beryl/compiz etc.. If that stuff works Gem should work.
> 
> I'm willing to do any testing needed, and any of the OSX devs can just
> as easily put ubuntu on their ppc machines and maybe just that will fix
> Frank's problems and make gem work on all opengl compatible hardware,
> even if it is not quite as fast as binary blob rendering.

Well, here's what I found out so far: 

It's not only my problem: Georg Holzman has it as well, AFAIR, and
Miha Tomsic has a bug report about it open on freedesktop.org [1].  As
I see it, it affects everyone trying to run Gem on Linux with Mesa/DRI
6.5 up, which means everyone without an NVidia card which means
probably more that a handful of people.

Mesa 6.5 did some major cleanup of MakeCurrentContext [2] which might
be related to our problem. However I have no idea where exactly Gem
and Mesa/DRI clash. I guess (wildly), that Gem is triggering some bug
in the Mesa/DRI layer. However as I'm GL-challenged I have no way of
pointing the DRI people to where that may be. 

What's even worse is that with M/DRI 6.5.2 Gem stopped rendering, as
reported by Miha, you and me.  While a crash when closing the Gem
window can be worked around by just never closing the Gem window,
broken rendering is a complete show stopper and doesn't even give a
useful coredump.

[1] https://bugs.freedesktop.org/show_bug.cgi?id=9204
[2] https://bugs.freedesktop.org/show_bug.cgi?id=8443

Ciao
-- 
 Frank Barknecht                 _ ______footils.org_ __goto10.org__