Re: Radeonfb hsync fudge factor?

On Wed, 24 Dec 2003, Sergey Vlasov wrote:

On Tue, Dec 23, 2003 at 06:43:17PM -0500, John Zielinski wrote:

quoted

What's the hsync fudge factor used for?

I noticed that the left edged of my screen moved a bit when I was
switching between 32/16/8 bpp modes and tracked it down to this.

The same thing here - both with Radeon VE QY and 8500LE (don't remember
the exact chip version).  Adding the opposite value to the fbset
parameters puts the image back into the place - so it looks like the hsync
fudge is unneeded at least with these chipsets.

Probably this fudge factor was needed for some early chips?

Yep, Mach64 needs one (but atyfb doesn't take care of it yet). So if you switch
between depths, the display may shift horizontally. I guess this is due to
different lengths of the dataflow paths for different color depths.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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


-------------------------------------------------------
This SF.net email is sponsored by: IBM Linux Tutorials.
Become an expert in LINUX or just sharpen your skills.  Sign up for IBM's
Free Linux Tutorials.  Learn everything from the bash shell to sys admin.
Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click