[libhid-discuss] Fwd: Error 13 on running test_libhid

[ankita prasad]

Hi All,

I found out that my HID device hasn't got a report descriptor. As in the
report descriptor is empty. Will I not be able to use libhid because of
this? I am pretty sure hid_force_open gives me a "device is not an HID
device because it has no report descriptors. Am I correct?

What can i do?

Thanks!
Ankita



---------- Forwarded message ----------
From: ankita prasad <prasad.ankita at gmail.com>
Date: Sep 11, 2007 4:46 PM
Subject: Error 13 on running test_libhid
To: libhid-discuss at lists.alioth.debian.org

Hi,

I plug in my HID device and  lsusb -vvv gives me this:

Bus 001 Device 019: ID 0694:0003 Lego Group
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0         8
  idVendor           0x0694 NI
  idProduct          0x0003
  bcdDevice            0.11
  iManufacturer           0
  iProduct                2 NIUSB Hub V0.11
  iSerial                 0
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           34
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xa0
      Remote Wakeup
    MaxPower              100mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Devices
      bInterfaceSubClass      0 No Subclass
      bInterfaceProtocol      0 None
      iInterface              0
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.10
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      37
         Report Descriptors:
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval              10

Here you will notice  this:
Report Descriptors:
           ** UNAVAILABLE **

After this i run test_libhid and i get a return code of 13, which is -"the
device is not an HID device". Attached is the output of test_libhid. Why do
i get this error when clearly the device gets enumerated as an HID device
initially. Is it because it has no report descriptors?

What am I doing wrong? Any help would be greatly appreciated!
Thanks!
Ankita




WARNING: hid_prepare_hid_descriptor(): failed to get HID descriptor for USB
device 001/011[0]:error sending control message: Broken pipe