Re: 2.6.0-test1-ac1 Matrox Compile Error

[James Simmons <jsimmons@infradead.org>]

> >    Also doing this kind of thing only covers up broken framebuffer 
> > drivers. Unfortunetly its going to take me months to cleanup and make the 
> > fbdev drivers behave right. 
> 
> We don't have months. Should we be talking about reverting to the rather
> solid 2.4 framebuffer side for 2.6 in this case ?

   Its not that the 2.5.X framebuffer layer is not solid. Except for the 
software cursor it behaves right. The issue I have is the quality of the 
framebuffer drivers. Lets take a example. In the new api we have two new
functions called check_var and set_par. Check_var's job is to test a 
passed in mode to see if the hardware can support it. It is not to alter 
or change any hardware states. The second function set_par does change the
hardware state. Lets look at the Mach64 driver. Mind you it does work and 
functions. We have 

static int atyfb_check_var(struct fb_var_screeninfo *var,
                           struct fb_info *info)
{
        struct atyfb_par *par = (struct atyfb_par *) info->par;
        struct crtc crtc;
        union aty_pll pll;
        int err;
                                                                                  
        if ((err = aty_var_to_crtc(info, var, &crtc)) ||
            (err = par->pll_ops->var_to_pll(info, var->pixclock,
                                        var->bits_per_pixel, &pll)))
                return err;
                                                                                  
#if 0   /* fbmon is not done. uncomment for 2.5.x -brad */
        if (!fbmon_valid_timings(var->pixclock, htotal, vtotal, info))
                return -EINVAL;
#endif
        aty_crtc_to_var(&crtc, var);
        var->pixclock = par->pll_ops->pll_to_var(info, &pll);
	return 0;
}

We can see here that we first pass var into aty_var_to_crtc to generate a
crtc struct. Then at the end we do the reverse and use that crtc to create
a var. This is horribly done. Now lets look at what is in set_par.

        if ((err = aty_var_to_crtc(info, var, &par->crtc)) ||
            (err = par->pll_ops->var_to_pll(info, var->pixclock,
                                        var->bits_per_pixel, &par->pll)))
                return err;

Its being called twice. Once in check_var and again in set_par. Mind you 
this works but the implementation is horribly done. I see this done alot 
in various drivers. The reason it was done this way was because people 
wanted a quick port to the new api without thinking much about it. 
   
    What makes me sad is I added accel hooks to speed up the console but I 
don't see anyone using there accel engines. Everyone is just using my soft 
accel functions :-( Using the soft accel was to be the exception not the 
rule.