Hi Xenos,
Thanks for following up. It's actually *any* USB device used with *any* Linux-based OS that causes the symptoms. Windows guest OSs seem to work better (brief testing shows no problems, but I rarely use the combination). I have a Linksys
WUSB54GC that causes the problem, but more easily testable is any simple USB mass storage device will cause the problem. Here is the relevant dmesg output from attaching a 2GB USB flash drive to an Ubuntu system running under Parallels.
[ 731.501445] usb 2-1: new high speed USB device using ehci_hcd and address 4
[ 731.632537] usb 2-1: configuration #1 chosen from 1 choice
[ 731.740050] scsi4 : SCSI emulation for USB Mass Storage devices
[ 731.747835] usb-storage: device found at 4
[ 731.747838] usb-storage: waiting for device to settle before scanning
[ 736.008819] usb-storage: device scan complete
[ 736.015461] scsi 4:0:0:0: Direct-Access Lexar JD Lightning 3000 PQ: 0 ANSI: 0 CCS
[ 736.043013] sd 4:0:0:0: [sdb] 3918848 512-byte hardware sectors (2006 MB)
[ 736.051803] sd 4:0:0:0: [sdb] Write Protect is off
[ 736.051810] sd 4:0:0:0: [sdb] Mode Sense: 43 00 00 00
[ 736.051812] sd 4:0:0:0: [sdb] Assuming drive cache: write through
[ 736.063997] sd 4:0:0:0: [sdb] 3918848 512-byte hardware sectors (2006 MB)
[ 736.072614] sd 4:0:0:0: [sdb] Write Protect is off
[ 736.072622] sd 4:0:0:0: [sdb] Mode Sense: 43 00 00 00
[ 736.072625] sd 4:0:0:0: [sdb] Assuming drive cache: write through
[ 736.072965] sdb: sdb1
[ 736.144133] sd 4:0:0:0: [sdb] Attached SCSI disk
[ 736.144990] sd 4:0:0:0: Attached scsi generic sg2 type 0
[ 740.841296] irq 9: nobody cared (try booting with the "irqpoll" option)
[ 740.841315] [<c015b594>] __report_bad_irq+0x24/0x80
[ 740.841323] [<c015b852>] note_interrupt+0x262/0x2a0
[ 740.841327] [<c015aab0>] handle_IRQ_event+0x30/0x60
[ 740.841331] [<c015c46b>] handle_level_irq+0xdb/0x110
[ 740.841334] [<c0106b1b>] do_IRQ+0x3b/0x70
[ 740.841338] [<c0105223>] common_interrupt+0x23/0x30
[ 740.841342] [<c015aa90>] handle_IRQ_event+0x10/0x60
[ 740.841346] [<c015c413>] handle_level_irq+0x83/0x110
[ 740.841349] [<c0106b1b>] do_IRQ+0x3b/0x70
[ 740.841352] [<c0105223>] common_interrupt+0x23/0x30
[ 740.841356] [<c012d68b>] __do_softirq+0x5b/0x110
[ 740.841360] [<c012d795>] do_softirq+0x55/0x60
[ 740.841362] [<c012da7d>] irq_exit+0x6d/0x80
[ 740.841364] [<c0106b20>] do_IRQ+0x40/0x70
[ 740.841366] [<c011e850>] pgd_dtor+0x0/0x50
[ 740.841371] [<c0102e00>] default_idle+0x0/0x60
[ 740.841373] [<c0105223>] common_interrupt+0x23/0x30
[ 740.841376] [<c0102e00>] default_idle+0x0/0x60
[ 740.841380] [<c011dba2>] native_safe_halt+0x2/0x10
[ 740.841383] [<c0102e3c>] default_idle+0x3c/0x60
[ 740.841385] [<c0102413>] cpu_idle+0x53/0xe0
[ 740.841388] [<c03e3a85>] start_kernel+0x325/0x3b0
[ 740.841392] [<c03e31f0>] unknown_bootoption+0x0/0x260
[ 740.841396] =======================
[ 740.841397] handlers:
[ 740.841398] [<d085b6a0>] (usb_hcd_irq+0x0/0x60 [usbcore])
[ 740.841410] [<d09e1640>] (snd_intel8x0_interrupt+0x0/0x240 [snd_intel8x0])
[ 740.841415] Disabling IRQ #9