Re: Re: Bug#226973: xserver-xfree86: [glint] second card at wrong resolution

On Wed, 31 Mar 2004, Sven Luther wrote:

On Tue, Mar 30, 2004 at 06:02:03PM -0500, Clint Adams wrote:

quoted

quoted

I believe that the cloack is different for 8bpp and 16 or 24 bpp, don't
remember exactly. At 8bpp, the max clock range is 230Mhz in the driver i
think. You looked at it, you have the hardware, you just have become the
resident expert on this issue :).

Ahh.  I tried increasing the 32bpp number to 150MHz, and was successfully
able to use a mode at 135MHz.  I am confused as to why the Pixmap setting
affects the ramdac frequency.  Is this a mistake or am I misunderstanding
something?  Would it be okay to set the maximum based on depth instead
of bitsPerPixel, or is bitsPerPixel wrong if it's set to 32 at a plain
24-bit depth?

I would have to look in the specs, but i believe the ramdac is only able
to push less pixels if those are of 16 or 32 bpp. This is the case for
all 3Dlabs chips prior to the permedia3. Look at the part in glint_driver.c
where these values are set. I have no explanation also, since my
involvement was with the permedia3, so maybe ask Alan Hourihane about
it.

If your graphics controller is limited by memory bandwidth, the maximum pixel
clock depends on the number of bits per pixels, since larger pixels mean more
memory bandwidth.

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
Free Linux tutorial presented by Daniel Robbins, President and CEO of
GenToo technologies. Learn everything from fundamentals to system
administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click