Re: NetBSD 5.0 and SPARCstation 5 not a lucky combination

[Michael <macallan%netbsd.org@localhost>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello,

On Jul 27, 2009, at 9:18 PM, der Mouse wrote:

> > > > Could the lack of wscons to manage the sparc graphics devices be
> > > > triggering the kind of unserialized register setting that der Mouse
> > > > described as a possible cause of this effect?
> > > Not directly, because that means that the kernel isn't scribbling on
> > > the framebuffer to draw console text; rather, it's punting to the
> > > PROM output routines.  At least, unless RASTERCONSOLE still exists
> > > and you're using it.
> > RASTERCONSOLE is what's set up in GENERIC for NetBSD/sparc 5.0.
>
> Oh, that makes it more interesting.  Then the console _is_ talking
> directly to the framebuffer.
>
> _Lack of_ wscons is unlikely to cause problems, it seems to me.

The acceleration code is slightly different.

> wscons combined with RASTERCONSOLE, I don't know what that would do;

It would #error out

> I haven't looked at sparc wscons at all.  I wonder if the other  
> observed cases
> were all using RASTERCONSOLE?  If it's on by default, quite likely so;
> perhaps that's where the bug is.

Probably, I dimly remember that the old rcons code draws at least the  
cursor and maybe all text by software and uses the blitter only for  
scrolling and rectangle fills.

> > Perhaps the next step is shutting that off, and seeing if the problem
> > persists.
>
> That would be an interesting datapoint.  With no wscons and no
> REASTERCONSOLE, console display _should_ go through the PROM  
> callbacks,
> AIUI; if _that_ misbehaves, it's probably what someone suggested about
> scrolling or other copies going on, though I have trouble imagining
> what would be doing it - something would have to be drawing on the
> framebuffer, which shouldn't be happening with just text-console I/O
> going on.

I'm pretty sure the PROM drawing routines for the cg6 use the blitter  
for at least a few things.

have fun
Michael

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (Darwin)

iQEVAwUBSm56/spnzkX8Yg2nAQKWkwgAndx1xG0ajELbmzFeciWmB8JpQpDWg2xr
/oTeqGYJnfJtGaqZKE21JPnl8oAEKJ27sRUCQ2Y9knzbX02TxPL02W1ELZOsBtHN
F2XDkCTt/T8cmq2/RC0TGHxz1vXrn81DjpU0a282ZibOnUz9kXn+QDULs6U4KJB3
dkrF+LSOmtsQcWmxL7N8iGr/u9XoDoCzep6J7c7a7cKpeU73hVQ1rsIDOYL55hNd
mS+AKBfXwESHA6DOQIoJTL5ONYZTfBRpO2AKEmtzv0my1XaGEynWJmnJj0/m13hJ
z3Qg4RzREKI3ZpLtMeec8IkvpwSqWgHkNWbq+JJ/90lN1VEl9Hk5xg==
=A0S4
-----END PGP SIGNATURE-----