How to resume USB hubs

["Gero Putzar" <gputzar@beckarndt.com.au>]

Hi,

when I tried to log in to my computer today, I realized that the usb ports
are not working anymore, therefore I've got no keyboard and no mouse
anymore. Logging in via ssh, I checked that besides that everything seems to
be running fine.

I googled around a bit and assume that the built in usb hubs (there seem to
be 4 or 5 of them) shut down maybe as a power saving feature. Does anyone
have an idea how to wake them up again?

If I plug in anything into one of the usb ports the /var/log/messages
doesn't show the usual message that the kernel recognized a new usb device.

I tried to write to the /sys/bus/usb/... files but unfortunately:
# echo on > /sys/bus/usb/devices/1-0\:1.0/power/level
bash: /sys/bus/usb/devices/1-0:1.0/power/level: No such file or directory

Is there a way to reset the usb hubs or to reinitialise the corresponding
kernel drivers or whatever deals with it? (I cannot reboot the computer at
the moment.) I tried:
# modprobe usbcore
FATAL: Module usbcore not found.

... and again without success:
# /etc/init.d/udev restart

I'm running the current Debian Lenny on a HP desktop with the standard Gnome
desktop.

Thanks, Gero.

I attached some output of how I tried to figure out the reason. Mouse and
keyboard were connected (via an external hub in the monitor) but that does
not seem to matter.

# ls /sys/bus/usb/devices
1-0:1.0  2-0:1.0  3-0:1.0  4-0:1.0  5-0:1.0  usb1  usb2  usb3  usb4  usb5
# ls -R /sys/bus/usb/devices/1-0\:1.0/
/sys/bus/usb/devices/1-0:1.0/:
bAlternateSetting   bInterfaceSubClass	ep_81	   uevent
bInterfaceClass     bNumEndpoints	modalias
usb_endpoint:usbdev1.1_ep81
bInterfaceNumber    bus			power
bInterfaceProtocol  driver		subsystem

/sys/bus/usb/devices/1-0:1.0/power:
wakeup

# cat /sys/bus/usb/devices/1-0\:1.0/power/wakeup 

# echo enable > /sys/bus/usb/devices/1-0\:1.0/power/wakeup 
bash: echo: write error: Invalid argument
# lsusb
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

# lsusb -v -s 1:

Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            9 Hub
  bDeviceSubClass         0 Unused
....
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           25
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0xe0
      Self Powered
      Remote Wakeup
    MaxPower                0mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         9 Hub
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      0 Full speed (or root) hub
      iInterface              0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0002  1x 2 bytes
        bInterval             255
Hub Descriptor:
  bLength               9
  bDescriptorType      41
  nNbrPorts             2
  wHubCharacteristic 0x000a
    No power switching (usb 1.0)
    Per-port overcurrent protection
  bPwrOn2PwrGood        1 * 2 milli seconds
  bHubContrCurrent      0 milli Ampere
  DeviceRemovable    0x00
  PortPwrCtrlMask    0xff
 Hub Port Status:
   Port 1: 0000.0100 power
   Port 2: 0000.0100 power
Device Status:     0x0003
  Self Powered
  Remote Wakeup Enabled