Subject: Re: GENERIC_31 Hangs on SE/30 w/Micron
To: Allen Briggs <>
From: Tres Hofmeister <tres@rap.ucar.EDU>
List: macbsd-development
Date: 04/17/1995 01:39:16
Allen Briggs writes:
: > : That kernel should disable the SE/30 video interrupts.  You are
: > : probably in a via2_intr loop trying to service the video interrupt.
: > 
: > 	Nope, the very same problem...
: Well, you probably are seeing the same problem, but the Micron Exceed
: isn't getting the interrupt cleared.  I'll try to find a way to postpone
: really dealing with this problem by implementing a work-around--probably
: tonight, if I can get past another bug that I'm working on.


	Is it a straightforward procedure to "disable the SE/30 video
interrupts?"  If so, and you could give me a hint, I'd try it.  I've
got sources from the sys.tar.gz file dated 4/15 from
installed at the moment.

	I'm excited (well, kind of... :) about this, as I found a hack
(through a little thought and a bit of experimentation) which makes the
Micron card in my SE/30 work with dt and X11R6.  Basically, I hardwired
(yeek!) the frame buffer size in grf.c.  That was the only value
which needed changing.  Apparently, the code which figures out the
frame buffer size:


	...produces the wrong result with the Micron card.  I assume
this has something to do with the "virtual video" capability of the
card, as Steven Lee suggested.  Setting gd_fbsize to 524288 (512K, the
actual amount of VRAM on the card) makes everything work.  I'm not sure
how to change this in a way which keeps all of the other video cards
out there working.  I just did this:

    if (gNumGrfDev == 0)
	gi->gd_fbsize = 524288;

	...near the bottom of grf.c.  Unfortunately, the kernel sources
I was working on are from March 13th or thereabouts, and I find that
pppd no longer works with kernels compiled from these sources.  And as
I mentioned above, the 4/15 sources which I just grabbed have the video
interrupt problem.  So currently I have to choose between PPP and my
Micron card... :(

	I wish I understood this stuff better.  Then maybe I could be
helpful, instead of just a pain in the neck! :)  Thanks yet again for
all of your help.  Any help or info. will be appreciated!

Tres Hofmeister                       Research Applications Program         National Center for Atmospheric Research