Re: [ACPI] [PATCH][RFC] fix ACPI IRQ routing after S3 suspend

["Stefan Dösinger" <stefandoesinger@gmx.at>]

> Something else to watch out for on ICH2 and similar chipsets is that, as
> long as the IRQ router is steering a PCI link onto a certain IRQ, LPC
> ISA device are blocked from triggering that IRQ via the SERIRQ protocol.
> But if we move the all the PCI links elsewhere, the SERIRQ is no longer
> blocked, and if some ISA LPC device is holding a high level, which
> normally wouldn't trigger IRQ's under ISA, then the IRQ line will get
> disabled because the PIC is probably set to level-trigger because it was
> PCI at one point. I've seen this happen with IRQ 12 when the BIOS
> decided there was no PS/2 mouse present so it could re-use the IRQ. The
> real cause is that the i850 has  a register that allows IRQ1 and IRQ12
> to be disabled on the LPC bus, and this register isn't restored on
> resume. This probably doesn't apply to IRQ11 on Stefan's system, though...
If I re-programm the IRQ to something else than IRQ10, the device doesn't 
resume too. So it's not only a problem of IRQ 11.

> Maybe it's time to look at the suspend/resume callbacks on the ipw2100
> driver, anyway.
The ipw2100 driver calls pci_disable_device in it's suspend handler. But I 
think the ipw2100 maintainers need help with suspend/resume because James 
Ketrenos can't test it on his own system.

I'll change another devices IRQ line to test if it's only an ipw2100 issue.

Stefan