libftdi Archives

Subject: Re: _ftdi_determine_max_packet_size reports wrong value in some cases

From: Xiaofan Chen <xiaofanc@xxxxxxxxx>
To: libftdi@xxxxxxxxxxxxxxxxxxxxxxx
Date: Sun, 26 Jun 2011 19:55:56 +0800
On Sun, Jun 26, 2011 at 7:49 PM, Алексей Косилин <kosilin75@xxxxxxxxx> wrote:
> Thank you for the prompt reply!
>
> Output of the lsusb is attached to this mail.

>From your lsusb output you can see the following. You can see that
the wMaxPacketSize is 64 for both EP1 IN and EP2 OUT. There is
no alternative setting to have zero bandwitdh (zero endpoint or
wMaxPacketSize=0, typically for ISOC device) in this case

      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0000  1x 0 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0

So you should probably fix the problem in your system and not
to change the libftdi codes.

What is your system?


-- 
Xiaofan

--
libftdi - see http://www.intra2net.com/en/developer/libftdi for details.
To unsubscribe send a mail to libftdi+unsubscribe@xxxxxxxxxxxxxxxxxxxxxxx

Current Thread