Re: [Linux-fbdev-devel] clipping

[James S. <jsi...@in...>]

> > I thought about this. Originally I did have this function but removed it.
> > WHat do you think Geert?
> 
> Yes, that's OK.
> 
> But I was most concerned about fb_ops.fb_imageblit(), since clipping impacts
> fb_image.data as well. IIRC, all (most?) current clipping implementations
> modify fb_image.{dx,dy,width,height} only, without updating fb_image.data.

Good point. Of course we could ignore pieces of data in that image instead 
of altering the data. Altering the entire data would be expensive.

> > > The other option (which I don't like) is just to check the passed
> > > fb_var_screeninfo in the put_var ioctl against the current console
> > > window size.  But this is not foolproof as we will not be sure of the
> > > resulting window size _after_ the fb_set_var() call.
> > 
> > Yuck!!! The other way is better.
> 
> Well, in between the calls to fb_ops.fb_check_var() and fb_ops.set_par() you
> can still perform that check. But it's indeed ugly.

Altering to the framebuffer via /dev/fb that would effect the tty should 
not remain after the final close of /dev/fb. Instead the console should 
reset to its previous state before we first opened /dev/fb.