From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755163AbYIWSbM (ORCPT ); Tue, 23 Sep 2008 14:31:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752795AbYIWSa5 (ORCPT ); Tue, 23 Sep 2008 14:30:57 -0400 Received: from [198.145.64.141] ([198.145.64.141]:43868 "EHLO coco.kroah.org" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751545AbYIWSa5 (ORCPT ); Tue, 23 Sep 2008 14:30:57 -0400 X-Greylist: delayed 975 seconds by postgrey-1.27 at vger.kernel.org; Tue, 23 Sep 2008 14:30:56 EDT Date: Tue, 23 Sep 2008 11:07:09 -0700 From: Greg KH To: cihan =?iso-8859-1?B?9np0/HJr?= Cc: linux-kernel@vger.kernel.org Subject: Re: USB driver problem with external hub Message-ID: <20080923180709.GB8661@kroah.com> References: <684433.70774.qm@web37502.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <684433.70774.qm@web37502.mail.mud.yahoo.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 20, 2008 at 04:35:03PM -0700, cihan öztürk wrote: > I am working on a device driver for providing connectivity to a Silabs > F340 board through USB. All the required software, including firmware > on the device side, USB device driver and user level libraries as well > as the application, are implemented. The system operates fine when > experimental communication is considered, in which dummy data is > simply sent and received betweeen the host and the device at Full > speed. The trouble comes when a USB external hub is used as a gateway > between the device and the host instead of directly connecting the USB > cable from device to the USB port of the PC. The kernel log states > that the transfer of urb failed due to -EPROTO(-71), which is defined > as protocol error. I found in some resources that this error can be a > result of (a) bitstuff error, or (b) no response packet received > within the prescribed bus turn-around time, or (c)hardware problems > such as bad devices (including firmware) or cables. > The hub is a Digitus product with 7 ports and works fine with other > USB devices such as the mouse on the same platform. > My kernel version is 2.6.18. Is this because you are using a USB 2.0 hub, connected via EHCI and your device is a 1.1 speed device? If so, this is a known issue with older kernel versions, and has partially been fixed in newer kernel releases. Please try 2.6.26 and let us know if that solves the issue. Or just use a 1.1 hub, that should also work. thanks, greg k-h