1

From lsusb -vv I can see, for example:

Bus 003 Device 002: ID 04b5:0680 ROHM LSI Systems USA, LLC 
Couldn't open device, some information will be missing
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x04b5 ROHM LSI Systems USA, LLC
  idProduct          0x0680 
  bcdDevice            1.54
  iManufacturer           1 
  iProduct                2 
  iSerial                 3 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0049
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower              100mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.12
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength    1929
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0014  1x 20 bytes
        bInterval              16
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0014  1x 20 bytes
        bInterval              16
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.12
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      53
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x84  EP 4 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval              10
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x03  EP 3 OUT
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval              10

I can see that it's an HID, but I'm not sure what I can use to determine if it's a keyboard or not. I thought maybe the bInterfaceSubClass or bInterfaceProtocol might indicate it, but they're 0, so I'm not sure if that means unspecified. The only other USB device that's output (besides hubs) is a Wacom, so that's probably just the touchpad. That makes me think that this device is really the keyboard. Also, xinput outputs "AT Translated Set 2 keyboard" so it doesn't seem like the keyboard is from the Wacom USB device.

I'm looking for criteria I can put in a script.

  • It's not a keyboard. A keyboard would have bInterfaceProtocol = 1. Notice that the same device can combine multiple interfaces (this is common for wireless kbd + mouse receivers). Your device has two, both with bInterfaceProtocol = 0 (None). – mosvy Jul 17 at 18:25
  • @mosvy You're right. I tried binding that usb device to usbipd which should have disabled it on the machine and the keyboard still worked. Looking through Xorg's log and udevadm info, I see mentions of ISA and i8042 with relation to the keyboard but no USB. Would you like to post your comment as an answer? It does answer the question. – JoL Jul 17 at 19:42

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