Re: [Linux-fbdev-devel] Some questions

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

On Thu, 2003-03-06 at 18:31, Sven Luther wrote:
> On Thu, Mar 06, 2003 at 06:05:37PM +0800, Antonino Daplas wrote:
> > Yes, there is.  Using the "stale" pixelclock, htotal and vtotal,
> > calculate hsync and vsync.  Compare this with your monitor's limit -- if
> > any fall outside, the entire mode, pixelclock and all is not valid.
> > 
> > (see fb_get_mode() and fb_validate_mode() in fbmon.c)
> > 
> > And if you use very narrow vsync and hsync ranges, then the "stale"
> > pixelclock will always most certainly be invalid.
> 
> BTW, do we have an easy way of knowing if it is an LCD or analog monitor
> which is attached to the card (or even a TV) ? I think the radeonfb
> knows how to do this, not sure though.
> 

There's an EDID parser in fbmon.c.  I think it will work only for the
PPC. This is currently used by rivafb and radeonfb. For the rest, either
we implement DDC or just have something similar to XF86Config's
HorizSync and VertRefresh.  We can load this either as a kernel/module
option or passed via ioctl/sysfs.  

I'm already doing this with the i810fb (as boot/module option), which
greatly simplified mode switching.

Tony