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I have an Apple aluminium keyboard with an integrated hub. On Mac OS X, I'm able to connect both my mouse and a USB pen drive while on Linux, the power limit is exceeded when connecting more than one device.

I'll be very happy if you are able to figure out why Linux is unable to reconfigure the USB port to supply more power.

Here is the output from lsusb -vvv:

Bus 003 Device 012: ID 05ac:1006 Apple, Inc. Hub in Aluminum Keyboard
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            9 Hub
  bDeviceSubClass         0 Unused
  bDeviceProtocol         1 Single TT
  bMaxPacketSize0        64
  idVendor           0x05ac Apple, Inc.
  idProduct          0x1006 Hub in Aluminum Keyboard
  bcdDevice           96.15
  iManufacturer           1 
  iProduct                2 
  iSerial                 3 
  bNumConfigurations      1
  Configuration Descriptor:
bLength                 9
bDescriptorType         2
wTotalLength           25
bNumInterfaces          1
bConfigurationValue     1
iConfiguration          0 
bmAttributes         0xa0
  (Bus Powered)
  Remote Wakeup
MaxPower              300mA
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     0x0001  1x 1 bytes
    bInterval              12

Update: The hub works perfectly if devices are enabled explicitly by entering the following command:

root@jonathans-imac:~# echo -n 1 > /sys/bus/usb/devices/1-1.2.1/bConfigurationValue

Visit http://lwn.net/Articles/186331/ to get more information on this issue.

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  • Need the lsusb on the devices yuo are trying to plug into the hub too.
    – psusi
    Nov 21, 2013 at 18:23

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