Shared ACPI/USB IRQ working in 2.6 but not in 2.4

From: Marcelo Tosatti
Date: Thu Nov 06 2003 - 07:15:57 EST


David van Hoose started having problems with USB on 2.4.23-pre5. USB
device and acpi were now using irq 20:

host/usb-ohci.c: USB OHCI at membase 0xe081a000, IRQ 20


20: 1 IO-APIC-level acpi, usb-ohci

Which makes the USB device not work.

With -pre4 the USB device was using interrupt 9, because acpi failed to
find the correct IRQ:

pci_irq-0302 [18] acpi_pci_irq_derive : Unable to derive IRQ for device 00:03.0
PCI: No IRQ known for interrupt pin A of device 00:03.0
host/usb-ohci.c: USB OHCI at membase 0xe081a000, IRQ 9

Now 2.6 assigns interrupt 20 to acpi and usb-ohci just like in
2.4.23-pre5+, but the USB device works!

Anyone has an idea why the interrupt sharing works with 2.6 but not with

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