PCI IRQ routing change broke PCMCIA/prism54 driver

Russell King rmk+pcmcia at arm.linux.org.uk
Tue Aug 17 04:47:04 EDT 2004

On Tue, Aug 17, 2004 at 09:29:10AM +0100, David Woodhouse wrote:
> On Sat, 2004-08-14 at 22:31 +0100, Russell King wrote:
> > When in Cardbus mode, there is only one interrupt line for child
> > devices, and this will be forwarded upstream from the bridge using
> > the Cardbus bridge IRQ itself.  Therefore, all child devices of a
> > Cardbus bridge will always have the same PCI IRQ as the Cardbus
> > bridge to which it is connected.
> Not always true. The TI PCI1420 can be configured to use two interrupt
> outputs, for example.

Please read the spec and what I wrote again.  In the case of PCI1420
configured to use both parallel PCI IRQs (INTA and INTB) then socket
1 (which is function 0) uses INTA and socket 2 (which is function 1)
uses INTB.

Therefore, all Cardbus devices connected to socket 1 use INTA and
all Cardbus devices connected to socket 2 use INTB.

So what I said _is_ true.

Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 PCMCIA      - http://pcmcia.arm.linux.org.uk/
                 2.6 Serial core

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