Re: Patches to fix aty128fb and xf400 r128 to work with both Rage128 and Rage128Pros

On Tue, 21 Mar 2000, Kevin B. Hendricks wrote:

Hi,

quoted

From the patches i see that the reference freq is still assumed to be
29.50Mhz
    /* Assume REF clock is 2950 (in units of 10khz) */
    /* and that all pllclk must be between 125 Mhz and 250Mhz */
    pll->reference_freq = 2950;
    pll->min_pll_freq   = 12500;
    pll->max_pll_freq   = 25000;

Yes, that's true.  Luckily, all of the Mac's use Rage128 cards with 2950 AFAIK.
I will keep looking through the manual to see if I can figure out a way to
determine this without a bios.

  If most Mac's use cards with 2950 then we should be fine for now, but for
the future we need to find a way to get this right.

quoted

From the comments in the xfree driver (and the ati docs) this isn't always
true:
    /* These probably aren't going to work for
       the card you are using.  Specifically,
       reference freq can be 29.50MHz,
       28.63MHz, or 14.32MHz.  YMMV. */

Yes I know.

quoted

 I'll be more than happy to get the patches in the xfree tree, even with
the reference_freq hardcoded its still an improvement.

Jacl Howarth just report a 30% performance increase in some x11perf tests
on XF 4.0 with the new patch versus the old values!  That makes me feel
better.

 Wow thats something :)

quoted

#ifdef __powerpc__ for this it should be better to see if the card has
an OF or BIOS rom first since that will allow people to keep using cards
with bios roms under ppc (i wonder if anyone is doing this)
Any ideas on how we can check if a card has OF or BIOS roms ?

Unforntunately, the current xf4 bios check does not work on some G3s and
G4's.  Literally tmp[] comes back with the right values that leads you to
believe that the Bios is there but the values for ref, the max and min pll,
read from the "Bios" etc are truly garbage (i.e. xlck reads as 0).  The
only reason it still worked was that none of the builtin modes fit the max
and min pll values so no modes were found so the r128_driver.c just
defaulted to the current fb mode which works.

I think a better check for a bios being present would detect the issue and
we code default to of values set in the pll registers next.

  The current code always assume that the ROM is a BIOS one, the 2 bytes
that it checks in the beggining are probably present in OF ati cards as
well so it thinks that everything is ok, we need to know if the card has
an OF rom or not (this is needed for other places in xfree as well the
int10 module will try to softboot OF cards also), i am sure there is a way
to find this i'll check the OF docs and see if i can find something.

Thanks!

Kevin

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