Thank you for the quick responses.
I looked at the console output from booting Linux and found the following:
[ 4.080850] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver [ 4.087411] ehci-pci: EHCI PCI platform driver [ 4.091938] ehci-platform: EHCI generic platform driver [ 4.097266] ehci-platform ARMH0D20:00: EHCI Host Controller [ 4.102864] ehci-platform ARMH0D20:00: new USB bus registered, assigned bus number 1 [ 4.110773] ehci-platform ARMH0D20:00: irq 149, io mem 0x7ffc0000 [ 4.133221] ehci-platform ARMH0D20:00: USB 2.0 started, EHCI 1.00 [ 4.140021] hub 1-0:1.0: USB hub found [ 4.143814] hub 1-0:1.0: 1 port detected [ 4.148092] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver [ 4.154388] ohci-pci: OHCI PCI platform driver [ 4.159000] usbcore: registered new interface driver usb-storage
I think this is where USB is initialized and I think the USB drivers are enabled. The IRQ error looks like the driver issued a command to the USB host and timed out waiting for the expected interrupt. I was thinking it could be an ACPI interrupt description problem or interrupt controller initialization problem. Do ya'll know a of a way to confirm that interrupts are working and routed correctly in Linux? Where in the Linux source code should I look for USB/interrupt setup and initialization? I think the problem would be in one of two places. The ACPI tables that are passed to Linux are missing or have incorrect information on interrupts or USB. Or the Linux kernel is using the ACPI tables incorrectly to initialize interrupts or USB.
Jeff