Index: [thread] [date] [subject] [author]
  From: Bob Barry <bobb@adsme.co.za>
  To  : Brian S. Julin <bri@tull.umassp.edu>
  Date: Tue, 11 May 1999 15:35:30 +0200

Re: Multiple ATI Video Cards

Brian -

The beav download hobbled to a halt, so I had a look with mc and probably
accomplished the same thing.  But setpci (companion to lspci, from package
pciutils) seems a safer and more intuitive tool for inspecting and changing the
pci registers.

Using field definitions from linux/drivers/pci/pci.h, the only relevant
differences between the first & second video cards was in COMMAND (bytes 4
& 5) which was 0087 on active card 0:b.0 and 0082 on idle card 0:c.0.  

But with cards' command register contents swapped by means of 
"setpci -s 0:b.0 command=82" and  "setpci -s 0:c.0 command=87", 
(confirmed by "lspci -vvx", which showed 0:b.0 disabled and 0:c.0 enabled)
GGI's "demo" still ran beautifully on card 0:b.0, but displayed trash on card
0:c.0 (after "export FRAMEBUFFER=/dev/fb1).  It seems like the hardware doesn't
really agree with the image in /dev/bus/pci.  Should driver init procedures
aty_init and atyfb_init be run again? And if so, how?  Modify fbset?

All suggestions welcome!

Bob Barry





Index: [thread] [date] [subject] [author]