Re: Linux 2.6.20-rc6 - sky2 resume breakage

[Ingo Molnar <mingo@elte.hu>]

* Jeff Garzik <jeff@garzik.org> wrote:

> >ok. Can you suggest any way for me to reproduce such a bug 
> >artificially on a test system? [i have both old and new systems, so 
> >if you can think of a way for me to trigger this i'd be happy to try]
> 
> Should be pretty easy.  With either the old-IDE driver or libata, 
> complete a command without acknowledging an interrupt.  For libata, 
> that means poking around in ata_host_intr() and avoiding well-built 
> hardware like AHCI.  Anything that uses ata_piix driver, basically all 
> Intel machines, should be applicable in the "not well built" 
> category... :)

ok, here's one victi^H^H^H^H testbox that seems to match your 
description:

 18:          3          0   IO-APIC-fasteoi   uhci_hcd:usb3, ohci1394
 19:    2413090          0   IO-APIC-fasteoi   uhci_hcd:usb2, libata
 22:        168          0   IO-APIC-fasteoi   HDA Intel
 23:          0          0   IO-APIC-fasteoi   uhci_hcd:usb1, ehci_hcd:usb5

so i should try to generate some missing ACK [this meaning a missing 
driver-level ack, right?] on IRQ#19's libata handler - and i should 
expect a screaming interrupt? Or non-working USB? Or both?

[ i can hunt for other hardware if this doesnt look broken enough to you
  :-) ]

	Ingo