[Dri-users] Memory required for 1280x1024x24-bit?

[Robert K. <rk...@so...>]

I've got DRI working with XFree86-4.0 on my Linux 2.4.2 box with a
16MB Matrox G400.  However, it currently only works in 16-bit; I haven't
gotten it to work in either 24 bit or (-depth 24 -fbbpp 32) mode.

Is there any way to do this?  Or do I have too little memory on my
G400?  There are two reasons why I think that I ought to be able to do
DRI on my G400 in 24 or 32 bit mode with only 16MB:

  * If I calculate the amount of memory needed (1024*1280*4), it seems that
    the screen itself would only require 5MB of memory out of the 16MB that
    the card has.

  * I am able to do hardware accelerated 3d rendering on the exact same card
    under XFree86-3.3.6 and the utah-glx project.

I don't know that memory is the problem, but I can't think of anything else
which would be causing DRI to fail in 24/32 bit mode when it doesn't in
16-bit mode.  Is there anything else in terms of configuration that I ought
to be looking for?

All the information I really have is that if I set LIBGL_DEBUG to 1 and run
glxinfo in 24 or 32 bit mode, I get this:

  libGL error: XF86DRIQueryDirectRenderingCapable returned false

I don't get that in 16-bit mode.

FWIW, I'm using the XFree86-4.0.2-0.1 rpm's from RawHide (rebuilt from the
SRC RPMs) and the Mesa-3.4-5 rpm's (again rebuilt from SRC RPMs) from the
same source.  (Actually, all were downloaded from rpmfind.net.)  These Mesa
RPMs *do* have the DRI patches applied, and indeed DRI does work in 16-bit.

-Rob