Re:Re: matroxfb problems with dualhead G400

Re:Re: matroxfb problems with dualhead G400

[Ghozlane Toumi]

Monday, September 03, 2001 4:51 PM, You wwrote:
> On  3 Sep 01 at 0:25, Benjamin Gilbert wrote:
> > [ software scroll back kills on dualhead ]
>
> You must boot your kernel with 'video=scrollback:0'. Otherwise your
> kernel die sooner or later... JJ's scrollback code does not cope with
> more than one visible console, so you must disable it if you have more
> than one display in the box.
>                                                 Petr Vandrovec

could we somehow detect in register_framebuffer that whe're going
multihead and disable software scrolling ?

I didn't look at the code so i don't know if it's feasible , just a
suggestion ..

ghoz

Re: matroxfb problems with dualhead G400

[Petr Vandrovec]

On  3 Sep 01 at 0:25, Benjamin Gilbert wrote:
> I've been trying to set up dualhead text console with matroxfb and a
> 16MB G400, with mixed success.  What I think I'm seeing is that the
> scrollback from the primary head, when it gets long enough (i.e., cat
> /boot/System.map), intrudes on the secondary head.  If the secondary
> head is set to the same resolution and bit depth as the primary, I

> Kernel is vanilla 2.4.9.  Let me know what other information you need
> from me.

You must boot your kernel with 'video=scrollback:0'. Otherwise your
kernel die sooner or later... JJ's scrollback code does not cope with
more than one visible console, so you must disable it if you have more
than one display in the box.
                                            Best regards,
                                                Petr Vandrovec
                                                vandrove@vc.cvut.cz
                                                

Re: matroxfb problems with dualhead G400

[Benjamin Gilbert]

On Mon, Sep 03, 2001 at 02:51:44PM +0000, Petr Vandrovec (VANDROVE@vc.cvut.cz) wrote:
> You must boot your kernel with 'video=scrollback:0'. Otherwise your
> kernel die sooner or later... JJ's scrollback code does not cope with
> more than one visible console, so you must disable it if you have more
> than one display in the box.

That doesn't fix it.  Shift-PgUp no longer works (of course), and
it's not immediately oopsing on me, but I still have the same type of
intrusion onto the secondary display.

--Benjamin Gilbert

Re: matroxfb problems with dualhead G400

[Petr Vandrovec]

On  3 Sep 01 at 22:31, Benjamin Gilbert wrote:
> On Mon, Sep 03, 2001 at 02:51:44PM +0000, Petr Vandrovec (VANDROVE@vc.cvut.cz) wrote:
> > You must boot your kernel with 'video=scrollback:0'. Otherwise your
> > kernel die sooner or later... JJ's scrollback code does not cope with
> > more than one visible console, so you must disable it if you have more
> > than one display in the box.
> 
> That doesn't fix it.  Shift-PgUp no longer works (of course), and
> it's not immediately oopsing on me, but I still have the same type of
> intrusion onto the secondary display.

And did you run 'fbset <anymode>' on first head after secondary head
was registered? You have to... After bootup first head uses all 16MB
for picture. When you load secondary head module, videoram is split
8MB for first head/8MB for second. And because of for correct
checking driver have to scan all your VCs for picture size, and refuse
to load if any resolution is over 8MB, I just decided to put this
task on user - run 'fbset -a -depth 8' after you load secondary head
module. It will shrink '-vyres' values for primary head displays
from their current value to maximum value possible for new memory
configuration.
                                            Petr Vandrovec
                                            vandrove@vc.cvut.cz
                                            

matroxfb problems with dualhead G400

[Benjamin Gilbert]

I've been trying to set up dualhead text console with matroxfb and a
16MB G400, with mixed success.  What I think I'm seeing is that the
scrollback from the primary head, when it gets long enough (i.e., cat
/boot/System.map), intrudes on the secondary head.  If the secondary
head is set to the same resolution and bit depth as the primary, I
can (sometimes) actually see the scrollback text go by on the
secondary.  The rest of the time, I just get garbage on the
secondary.  Scrolling text on the second head, OTOH, does not affect
the primary head.  Occasionally, scrolling text on the primary head
will cause a kernel oops, although this isn't consistent; it happens
less than 25% of the time.

I've tried various combinations of video resolutions and matroxfb
boot-time options, but haven't really determined anything conclusive. 
The problem lasts from boot until the first time that the fbdev
resolution is changed on the primary monitor; then the problem goes
away.  This seems to be true regardless of the initial resolution of
the primary monitor.  Setting "video=matroxfb:nopan" makes the
problem rarer, but it still seems to pop up occasionally -- I oopsed
once while testing this.

All of this is before starting XFree86, so X isn't a factor here.

Kernel is vanilla 2.4.9.  Let me know what other information you need
from me.

Thanks in advance
--Benjamin Gilbert