[Linux-fbdev-devel] Re: Who is stomping PCI config space?

[Egbert Eich]

Benjamin Herrenschmidt writes:
 > > 
 > > If we leave the whole card turned off I can't access the interrupt
 > > status registers to acknowledge the interrupt and shut it off.
 > 
 > Also, some cards won't let you switch VGA access decoding off.

This is what I suspect. I had some success with the generic VGA disable
code but our mileage may vary.

 > 
 > > Does this approach work for X? Where is the code that does this at VT
 > > switch time?
 > > 
 > > On VT enter X would need to:
 > > 1) shut off interrupts
 > 
 > Not possible (system interrupts). Unless it does it on the card itself,
 > which is a per-driver thing.

How do we deal with interrupts from VGA cards that we don't have a 
driver for? We don't service interrupts in this case either.
Can't we unregister the interrupt handler until everything
is set up right? Maybe a dump idea...
Also there is a generic VGA register to control interrupts.


Egbert.