Re: [PATCH] RE: 2.4.5-ac14 through to 2.4.6-ac1 fdomain.c initialisation for shared IRQ

[David Weinehall <tao@acc.umu.se>]

On Thu, Jul 05, 2001 at 07:16:26PM +0100, Alan Cox wrote:
> > I have recently had a problem with the fdomain driver initialisation and
> > have found the problem to be the way in which it requests the irq. Here is
> > my patch that has so far work ok.
> 
> I've seen this patch before. It needs at least one change
> 
> > -			     do_fdomain_16x0_intr, 0, "fdomain", NULL);
> > +      retcode = request_irq( shpnt->irq,
> > +			     do_fdomain_16x0_intr, SA_SHIRQ, "fdomain", shpnt);
> 
> Only set SA_SHIRQ if PCI - say -
> 
> 		pdev?SA_SHIRQ:0
> 
> The other problem is that the code doesnt have support for handling IRQ
> source checking, so if the line it shares with generates interrupts we might
> sometimes do the right thing
> 
> I have a long outstanding request with adaptec (who bought future domain)
> for the info needed to fix this, but obviously its a dead product, from a
> bought company and hardly on their priorities.
> 
> I suspect the IRQ handler needs to either
> 
> A.	Check bit 0 of the status port and return 
> 
> B.	Check bit 4 or bit 9 of the interrupt control register
> 
> Without docs someone would need to play with the various combinations and
> see what happened

Uhmmm, an idea would be to look in fd_mcs.c as that driver already has
working support for irq-sharing.


/David
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