Re: [Linux-fbdev-devel] problem with gen_update_var

[Antonino D. <ad...@po...>]

On Tue, 2002-06-18 at 03:27, James Simmons wrote:
> 
> > Hi,
> >
> > gen_update_var will break panning/wrapping since it passes info->var to
> > fb_pan_display.  However, fbcon updates display->var.
> 
> It works. The var info struct fb_info is always the foreground console.
> Notice gen_update_var is only called when it is the foreground console.
> 
> 
In ywrap_up in fbcon.c, it has this code:

    p->var.xoffset = 0;
    p->var.yoffset = p->yscroll*fontheight(p);
    p->var.vmode |= FB_VMODE_YWRAP;
    p->fb_info->updatevar(unit, p->fb_info);

(*p is struct display).  gen_update_var will call pan_display(info->var,
con, info).  But as can be seen, info->var is not updated by ywrap_up.  

Unless, the low-level driver's implementation is to get the offsets 
from fb_display[con].var, that's the only time it will work.  But it
will break userland apps that will call pan_display(var, con, info)
expecting that the offsets contained in the passed var parameter will be
updated.

Tony