[Linux-fbdev-devel] Re: Choosing the correct framebuffer configuration

[Michel <mi...@da...>]

On Sun, 2005-08-07 at 12:53 -0400, Jon Smirl wrote:=20
> On 8/7/05, Michel D=C3=A4nzer <mi...@da...> wrote:
> > On Sun, 2005-08-07 at 18:14 +0200, Benjamin Herrenschmidt wrote:
> > > > > The problem is that the radeonfb driver sees bpp =3D 32 and then =
sets
> > > > > rgbt =3D 8/8/8/8. It stomps rgbt without looking at it.
> > > >
> > > > Looks like a radeonfb bug.
> > >
> > > It's not a bug :) radeonfb doesn't support anything but that format f=
or
> > > now.
> >=20
> > According to Geert's rules, it should fail instead of rounding down
> > r/g/b.
>=20
> One problem with these rules is that it makes it hard to determine
> what is the best config available. I can't just set in 255BPP and then
> let it tell me the best available config.

If an app doesn't know its _minimum_ requirements, I doubt it wants 16
bits per component. If an app really needs the 'best' (how is that
defined?) config, it can try setting the best it supports and then lower
the requirements until it hits something that the driver supports.

> What config should I get if everything is zero, BPP and rgbt?
> According to the rules this is an error,=20

I haven't seen such a rule, where is it?

> should it instead return the best config?

That sounds to me like the app doesn't care, so the driver can return
whatever it pleases.


--=20
Earthling Michel D=C3=A4nzer      |     Debian (powerpc), X and DRI develop=
er
Libre software enthusiast    |   http://svcs.affero.net/rm.php?r=3Ddaenzer