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

On Thu, Apr 01, 2004 at 08:51:02AM +0200, Sven Luther wrote:

On Thu, Apr 01, 2004 at 01:41:22AM -0500, Branden Robinson wrote:

quoted

On Wed, Mar 31, 2004 at 11:10:02AM -0500, Clint Adams wrote:

quoted

quoted

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.

I'm unclear on the differences between 24 bpp and 32 bpp and how this
relates to internal pixmap format.

Some hardware uses a "packed-pixel format"; that is, 4 24-bit pixels are
encoded in 3 32-bit words (what Intel calls "DWORDS", I think).

Yeah, DWORDS, because they are stil living in the era of 16bit hardware :)

quoted

Other hardware tosses in a zero byte with every 32-bit "DWORD" transfer.

Well, the permedia2 should support both formats, depending on chosen
mode.

Well, maybe this is what is going on.  Maybe Solaris is using a
packed-pixel format, and XFree86 is using zero-padded format.

That is, assuming it's the RAMDAC's job to understand the pixel format,
and that some part isn't stuck in front of it to give it a standardized
format.  I wouldn't know.

-- 
G. Branden Robinson                |     That's the saving grace of humor:
Debian GNU/Linux                   |     if you fail, no one is laughing at
branden@debian.org                 |     you.
http://people.debian.org/~branden/ |     -- A. Whitney Brown