Re-scan of USB-attached devices ?

[Mikus Grinbergs]

My setup includes multiple external devices attached to the XO.  The
particular system I am describing has an USB hub plugged into the XO,
with an USB keyboard and an USB trackball plugged into that hub.

On an XO-1 with os11, I was unplugging/replugging (directly into the XO)
an external USB microscope (and doing 'lsusb').  I lost my external
keyboard (and trackball), and switched to the text console.  While
there, I was surprised to see libertas-related messages showing up:

> [ 1491.577108] usb 2-3: new high speed USB device using ehci_hcd and address 7
> [ 1491.777700] uvcvideo: Found UVC 1.00 device Vimicro USB2.0 UVC PC Camera (0ac8:3610)
> [ 1491.788702] input: Vimicro USB2.0 UVC PC Camera as /devices/pci0000:00/0000:00:0f.5/usb2/2-3/2-3:1.0/input/input10
> [ 1496.443445] libertas: command 0x000b timed out
> [ 1496.447986] libertas: Timeout submitting command 0x000b
> [ 1496.453234] libertas: PREP_CMD: command 0x000b failed: -110
> [ 1496.459273] Resetting OLPC wireless via EC...
> [ 1496.466826] usb 2-1: USB disconnect, address 2
> [ 1496.473733] usb8xxx: URB in failure status: -108
> [ 1497.286884] usb 2-1: new high speed USB device using ehci_hcd and address 8
> [ 1512.447005] usb 2-1: device descriptor read/64, error -110
> [ 1527.706727] usb 2-1: device descriptor read/64, error -110
> [ 1527.936820] usb 2-1: new high speed USB device using ehci_hcd and address 9
> [ 1543.096827] usb 2-1: device descriptor read/64, error -110
> [ 1558.357043] usb 2-1: device descriptor read/64, error -110
> [ 1558.587134] usb 2-1: new high speed USB device using ehci_hcd and address 10
> [ 1569.036844] usb 2-1: device not accepting address 10, error -110
> [ 1569.177104] usb 2-1: new high speed USB device using ehci_hcd and address 11
> [ 1579.637061] usb 2-1: device not accepting address 11, error -110
> [ 1579.654192] hub 2-0:1.0: unable to enumerate USB device on port 1
> [ 1580.100441] usb 1-1: new full speed USB device using ohci_hcd and address 5
> [ 1580.339397] usb 1-1: not running at top speed; connect to a high speed hub
> [ 1581.273251] usb8xxx: Firmware ready event received
> [ 1581.290296] libertas: 00:17:c4:14:2a:3a, fw 5.110.22p23, cap 0x000003a3
> [ 1581.319503] libertas: wlan0: Marvell WLAN 802.11 adapter
> [ 1581.361652] libertas: PREP_CMD: command 0x0074 failed: 2
> [ 1581.394446] usb8xxx: Firmware does not seem to support PS mode
> [ 1581.414283] libertas: PREP_CMD: command 0x0043 failed: 1
> [ 1581.431584] libertas: HOST_SLEEP_CFG failed 1
> [ 1581.669303] udev[876]: renamed network interface wlan0 to eth0
> [ 1581.770262] ADDRCONF(NETDEV_UP): eth0: link is not ready
> [ 1584.322346] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
> [ 1592.093477] msh0: no IPv6 routers present
> [ 1594.516734] eth0: no IPv6 routers present

It appears to me that in this instance, when finding a new USB device
present, the entire USB-device tree is being "re-scanned" -- resulting
in the reinitialization of the radio chip on the XO-1 (and probably also
in the disconnect of the external-keyboard).


mikus