Re: a hint on /dev/grf3 problems..

["Joerg Lehners" <Joerg.Lehners%Informatik.Uni-Oldenburg.DE@localhost>]

On Thu, 24 Jun 1999, Ignatios Souvatzis wrote:
> On Thu, Jun 24, 1999 at 10:58:54AM -0600, Michael L. Hitch wrote:
[...]
> >   It looks like the other ite drivers don't touch any hardware registers,
> > and just stuff the appropriate data into memory.  The ite_cl.c driver does
> > a couple of SetTextPlane() calls, which I presume clobber the graphics mode.
> yes. For grf_cl, this is (from ...reg.h):
> #define SetTextPlane(ba, m) \
>         do { \
>                 WGfx(ba, GCT_ID_READ_MAP_SELECT, m & 3 ); \
>                 WSeq(ba, SEQ_ID_MAP_MASK, (1 << (m & 3))); \
>         } while (0)
> 
> the Wxxx() calls do accesses to subsets of the VGA registers.
> 
> >   I just tried the following patch on my system and it seems to cure the
> > problem [just ignores console output while in graphics mode]:
> 
> --- /opt/NetBSD-1.4/src/sys/arch/amiga/dev/ite_cl.c   Thu Mar 25 19:27:17 1999
> +++ sys/arch/amiga/dev/ite_cl.c       Wed Jun 23 19:06:19 1999
> @@ -161,6 +161,8 @@
>       unsigned char attr;
>       unsigned char *cp;
>  
> +     if (ip->flags & ITE_INGRF)
> +             return;
>       attr =(unsigned char) ((mode & ATTR_INV) ? (0x70) : (0x07));
>       if (mode & ATTR_UL)     attr  = 0x01;   /* ???????? */
>       if (mode & ATTR_BOLD)   attr |= 0x08;
> 
> Thanks Michael... I think you found the problem. I wasn't aware that the
> other vga-style drivers don't touch the registers on text output.
> [...]

I think the modification should not only apply to the function
cl_putc() but also to cl_clear() and cl_scroll().

With the patch above I can reproduce the following effects:
If the cursor is high enough so that the console does not need
to scroll when putting out a kernel message while the X-Server
starts or runs, there are no screen distortions.
If the screen needs to scroll while the X-Server is starting
or running, I'll get a distorted screen.

The kernel I use is custom built, but without changing DIAGNOSTIC.

  Joerg
-- 
Mail: Joerg.Lehners%arbi.Informatik.Uni-Oldenburg.DE@localhost
Real: Joerg Lehners, Informatik ARBI, Uni Oldenburg, D-26111 Oldenburg
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