Re: [Linux-fbdev-devel] Supporting various depth

[Geert U. <ge...@li...>]

On Wed, 13 Jun 2001, James Simmons wrote:
> > > int fb_set_var(struct fb_var_screeninfo *var, struct fb_info *info)
> > > {
> > >     int oldbpp, err;
> > > 
> > >     if (memcmp(&info->var, var, sizeof(var))) {
> > >         if ((err = info->fbops->fb_check_var(var, info)))
> > >                 return err;
> > 
> > This is not correct, since it first overwrites the old var, then checks whether
> > the new one is valid. If that test fails, you're left with an invalid var in
> > info->var.
> 
> That is a memory compare. It checks to see if the purposed mode is the
> same as the current mode. If not then fb_check_var is called to test the
> new var. info->var = var only if var->activate == FB_ACTIVATE_NOW and
> their is a set_par function. You can set info->var = *var before set_par
> is called because we trust check_var did its job. 

Sorry, my twisted mind read memcpy() instead of memcmp().

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@li...

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds