Messages in this thread | | | Date | Fri, 16 Nov 2007 11:20:51 +0000 (GMT) | From | "Maciej W. Rozycki" <> | Subject | Re: question on odd APIC behavior |
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On Fri, 16 Nov 2007, Oliver Neukum wrote:
> > > On irq 20, there's an UHCI, on irq 19 is an EHCI. For every interrupt on 20 > > > there's a spurious interrupt on 19. USB devices on bus of the controller on 20 > > > work. So I know all interrupts are seen. ERR does not increase. Interrupts > > > for devices on the bus of the controller on 19 arrive at 19 only. > > > > I suggest you try to sort it out with the maintainers of the UHCI and > > EHCI drivers then. > > They are innocent. This laptop really delivers an interrupt twice.
Perhaps, but these drivers are involved and the device-specific knowledge will help tracking down the cause. I have general experience on how interrupts work, including on APIC-based systems, but I have no idea how UHCI and EHCI devices work in this area and, in particular, how you know an interrupt coming from the line #19 is related to one on the line #20 and then a spurious one if not recorded as ERR or otherwise unclaimed (which would be reported as "irq 19: nobody cared").
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