[libhid-discuss] Broken pipe error in hid_prepare_hid_descriptor

[Charles Lepple]

You may have to check through the Linux kernel source to see exactly  
what kinds of errors trigger EPIPE.

>         Report Descriptors:
>           ** UNAVAILABLE **

Are you running lsusb as root, or with write permissions to the /proc/ 
bus/usb/ or /dev/bus/usb/ device node?

> I have blacklisted the HID device from the kernel driver and then  
> run test_libhid. When hid_force_open calls  
> hid_prepare_hid_descriptor, the usb_control_msg call in  
> hid_prepare_hid_descriptor returns a broken pipe error an extract  
> from the output when test_libhid is run is as follows:

You seem to be on the right track for debugging this, but if lsusb  
can't read the descriptors, you may have a problem with the USB  
device firmware or its interactions with the Linux USB kernel drivers.

-- 
Charles Lepple
clepple at ghz.cc