EXA framework question

Mohan Parthasarathy suruti94 at gmail.com
Sat Jun 14 19:50:48 PDT 2008

On 6/14/08, Steven J Newbury <steve at snewbury.org.uk> wrote:
> On Sat, 2008-06-14 at 06:47 -0700, Mohan Parthasarathy wrote:
> > Hi,
> > i am not sure i understand. X itself does not need it but still needed
> >  for e.g., text mode console access. Is that what you mean ?
> > Mohan
> EXA is completely unrelated to fbdev drivers.  DRM will eventually
> largely replace fbdev drivers once kernel modesetting support goes
> mainstream, at that point X will be using the kernel modesetting
> support.  At present, fbdev provides modesetting for console (non-X -
> DirectFB, text etc) only while all current X video drivers have built-in
> modesetting either through VBIOS calls or by programming the hw
> directly. EXA is an acceleration infrastructure for X replacing XAA and
> makes use of DRM in some cases to provide higher performance.

Great. That clarifies a lot. In EXA, the X driver in userspace controls
the hardware through MMIO and there is no kernel component at all
except for the modesetting unlike the older XAA model where there
was an X driver and the framebuffer driver. Right ?

There is also a DDX driver for fbdev which uses the kernel fbdev driver
> to setup the graphics but provides no hw acceleration.  Various eariler
> versions of some video drivers featured a "UseFBDev" option which used
> fbdev for modesetting.

I am a little confused by this. Before EXA, XAA framework used the
framebuffer driver
for the acceleration. You are talking about two drivers above : DDX driver
to setup
graphics and some drivers that used "UseFBDev" for modesetting. Could you
clarify ? Sorry, i am pretty new to all these..


> > On 6/14/08, Maarten Maathuis <madman2003 at gmail.com> wrote:
> > > On 6/14/08, Mohan Parthasarathy <suruti94 at gmail.com> wrote:
> > >> Hi,
> > >>
> > >> A basic question. If all the drivers are converted to use EXA
> framework,
> > >> then we don't need any drivers
> > >> in the kernel (everything in drivers/video), fbdevhw is not needed
> etc. Is
> > >> that right understanding ?
> > >>  Or i am completely off ?
> > >
> > > EXA is only for X drivers, you would still need kernel drivers for
> > > framebuffers (for example).
> > >
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.x.org/archives/xorg/attachments/20080614/4d177125/attachment.html>

More information about the xorg mailing list