Hard lockup switching to X from vc; Matrox G400 AGP

Hard lockup switching to X from vc; Matrox G400 AGP

[Chris Rankin]

REF: Linux 2.4.5, 2.4.4, 2.4.3 (and probably earlier);
     devfs;
     SMP (dual PIII);
     < 1GB main memory

Hi,

Has anyone noticed their Linux box lock up hard (as in cannot even be
pinged from the local network) when switching from a text vc to a vc
running X? This has happened for me even without the mga.o and
agpgart.o modules being loaded. My current workaround has been to swap
out the Matrox-supplied mga_drv.o and mga_hal_drv.o modules and
replace them with the ones from the standard X 4.03 distribution, but
these are userspace objects and shouldn't be capable of bringing the
kernel down. (Like I said, the machine can't even be pinged.)

My best guess is that the mga_hal_drv.o object is ticking an obscure
kernel bug. I am raising this with the Matrox support line as well.

Cheers,
Chris

Re: Hard lockup switching to X from vc; Matrox G400 AGP

[Alan Cox]

> out the Matrox-supplied mga_drv.o and mga_hal_drv.o modules and
> replace them with the ones from the standard X 4.03 distribution, but
> these are userspace objects and shouldn't be capable of bringing the
> kernel down. (Like I said, the machine can't even be pinged.)

Not really. The matrox code and X server run priviledged and bang on hardware
directly. Its quite easily an X11 bug. Nice to know the free software one
works better than the vendors 8)

Re: Hard lockup switching to X from vc; Matrox G400 AGP

[Ben Twijnstra]

Hi Chris,

Seen the same behaviour; you're not alone. I'm running XF86 4.0.3 with a G400. My guess is that mga_drv goes into some local loop while trying to restore the display. mga_drv at that moment has I/O privileges and if it hangs, Linux hangs too.

Grtz,


Ben

Re: Hard lockup switching to X from vc; Matrox G400 AGP

[Chris Rankin]

Hi, thanks for confirming this. But if it's Matrox's code (we are
talking about the mga_hal_drv.o module for X, correct?) then the ball
is in their court. Has anyone reported this to them so that they can
fix it?

Cheers,
Chris
 
> On Mon, May 28, 2001 at 12:24:50AM +0200, Ben Twijnstra wrote:
> > Hi Chris,
> > 
> > Seen the same behaviour; you're not alone. I'm running XF86 4.0.3 with 
> > a G400. My guess is that mga_drv goes into some local loop while trying 
> > to restore the display. mga_drv at that moment has I/O privileges and if 
> > it hangs, Linux hangs too.
> 
> It is problem with their driver. Their are resetting too much of
> hardware state during mode switches and if someone accesses memory
> at that moment, whole thing locks up your PCI bus - if you have ATX
> box, try hitting poweroff button next time it lockups. If poweroff
> does not work you'll have bad time to get it debugged. If poweroff
> button works, you can try kdb...
> 
> On my machine it is 100% reproducible if I run 'fbtv -k' and start X.
> It will die immediately.

Re: Hard lockup switching to X from vc; Matrox G400 AGP

[Rafael Herrera]

I experienced lost of the signal when switching from X to the console
when booting with vga=ext or some of the graphic modes. It was reported
here that the problem was the Matrox drivers.

Recently, with kernel 2.4.4+ and XFree 4.0.3 (@1280x1024/head)+ Matrox
drivers (http://matrox.com/mga/support/drivers/files/linux_06.cfm) and
booting with vga=794 (1280x1024) I have not had problems. I've a G450.

-- 
     Rafael

Re: Hard lockup switching to X from vc; Matrox G400 AGP

[Rahul Karnik]

Hi fellow Matrox users,

Maybe I can help in reporting your problems to Matrox.
Can you give me some more info as to XFree 86 version
and Matrox driver version?

-Rahul


=====
------------------
Rahul Karnik
rakarnik@yahoo.com

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