Re: [Linux-fbdev-devel] setcolreg vs. 565

[Michel <mic...@ii...>]

On Sat, 2001-11-24 at 13:11, Benjamin Herrenschmidt wrote:
> >On Fri, 2001-11-23 at 16:34, Benjamin Herrenschmidt wrote:
> >> >Except that you can't change gamma, or am I on the wrong track here?
> >>=20
> >> Well, X fbdev driver can only do truecolor afaik. It does send a
> >> linear gamma table to the driver which is required anyway as the
> >> fbdev themselves can be directcolor, but for real directcolor
> >> support in X, we would probably need some other changes.
> >
> >So why does xgamma work with it?
>=20
> I don't know ;) I've looked at the source and it clearly states
> supporting only truecolor, but well, maybe xgamma is taking some
> weird path within the X server ?

No, it uses the very general path of calling the driver's LoadPalette()
function, fbdevHWLoadPalette() in this case, which uses FBIOPUTCMAP
ioctl.

The comment apparently only applies to X visuals, I must confess I don't
really know the difference there either. :)


> BTW, I found my bug and now have 5:6:5 working properly. I'll
> implement 5:5:5 and backport some of my fixes to aty128fb as
> in it's current state, I beleive it's gamma setting doesn't
> work properly neither. You get a clear picture because of the
> hack that force a linear ramp when setting LUT entry 0, but
> that hack can be removed if the rest is done properly ;)

So directcolor works correctly now? Great!


--=20
Earthling Michel D=E4nzer (MrCooper)/ Debian GNU/Linux (powerpc) developer
XFree86 and DRI project member   /  CS student, Free Software enthusiast