[sane-devel] HP 7450C libusb problems (a little bit more info)

Sietse Achterop sietse@cs.rug.nl
Sun, 20 Jun 2004 14:44:19 +0200


Concerning the bulk timeouts seen with the avision
backend amongst others here a little bit more info.
It is a follow up of my earlier report in


   some more info is given when the timeout occurs:
       (this is mostly after 1 or 2 successful bulk transfers)

   [sanei_usb] sanei_usb_read_bulk: trying to read 22656 bytes
   USB error: error reading from bulk endpoint 0x83:
               Invalid or incomplete multibyte or wide character
   [sanei_usb] sanei_usb_read_bulk: read failed:
               Invalid or incomplete multibyte or wide character
   USB error: could not clear/halt ep 131: Protocol error

   I found the "USB error" originating in libusb, but I can't find
   where the "Invalid or incomplete .." message comes from.
   So I can't see whether it maybe is significant.

   after "modprobe uhci_hcd debug=2"  (or 3)
   NO extra information is put into /var/log/kern.log

Finally, is there anything else that I could do or test?
I was hoping to make a smaller testcase than the test.c program
in sane-backends/frontend