Re: [Linux-fbdev-devel] [PATCH] aty128fb 15/16 bit cleanup

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

Geert Uytterhoeven wrote:
> 
> On Fri, 22 Jun 2001, Michel Dänzer wrote:
> > Geert Uytterhoeven wrote:
> > > On Fri, 22 Jun 2001, Michel Dänzer wrote:
> > > > While this now works perfectly in X for both depth 15 and 16 as well as in
> > > > console for fbset -depth 16 -rgba 5,5,5,0 , some colors are wrong for
> > > > fbset -depth 16 -rgba 5,6,5,0 . It's not clear to me whether the palette
> > > > for
> > >
> > > Funny, I have similar problems with atyfb and 565 (didn't manage to get X
> > > working yet, since I still use 3.3.6 which seems to pass invalid parameters
> > > when being `strict' in the color bitfield checking).
> >
> > I know, Michael Schmitz forwarded your patch to me, it helped me a lot,
> > thanks.
> >
> > > > 565 should have 32 or 64 entries.
> > >
> > > 64 of course. But red and blue should fill the first 32 entries only.
> >
> > Okay, but why do you allocate a cmap with only 32 entries then? Do you
> > extrapolate the missing green entries in this line?
> >
> >            green = info->palette[(2*regno) & 0xff].green;
> >                                  ^^^^^^^^^^^^^^^^
> > I don't understand what this is supposed to do. As 0<regno<32, (2*regno)
> > can't
> 
> For palette index regno, red and blue are stored in a different DAC entry
> than green. So when I store red and blue, I have to make sure I write the
> correct green value there. That green value is palette[regno*2].green.
> Follow the fall-through and merge the code:
> 
>     aty_st_dac(regno << 2, palette[regno/2].red, green,
>                palette[regno/2].blue);
>     aty_st_dac(regno << 3, red, palette[(2*regno) & 0xff].green, blue);

Okay, I think I understand now. XFree86 actually sends 64 entries so that has
to be dealt with.


I'm going to use the 1 1/4 hours on the train for some more hacking...


-- 
Earthling Michel Dänzer (MrCooper)    \   Debian GNU/Linux (powerpc) developer
CS student, Free Software enthusiast   \        XFree86 and DRI project member