From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757756AbZCDV7m (ORCPT ); Wed, 4 Mar 2009 16:59:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753302AbZCDV7e (ORCPT ); Wed, 4 Mar 2009 16:59:34 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:56877 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752902AbZCDV7d (ORCPT ); Wed, 4 Mar 2009 16:59:33 -0500 Date: Wed, 4 Mar 2009 16:59:28 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: "Eric W. Biederman" cc: Greg KH , Ingo Molnar , Randy Dunlap , Yinghai Lu , Sarah Sharp , , Linux Kernel Mailing List , Andrew Morton Subject: Re: EHCI debug documentation In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Mar 2009, Eric W. Biederman wrote: > Greg KH writes: > > > * Randy Dunlap wrote: > >> Yinghai Lu wrote: > >> > b. netchip USB debug cable > >> > >> http://www.plxtech.com/products/NET2000/NET20DC/default.asp > > > > I have reports that the newer version of this device does not work on > > Linux as it isn't enumeratable as a "real" usb device on one end. > > > > I don't have one of these new devices yet to test it out, has anyone > > else heard of this problem? > > With the first generation of devices I remember they were peculiar and > finicky. I don't recall the exact details but I remember the devices > able to get into weird states that may resemble what you describe. Those devices were a little peculiar in that they were powered only on one side. That is, they would take bus power only from the right-hand connector (looking at the face with the PLX logo). So if you plugged in only the left side, the device would not show up or enumerate. But if you plugged in both sides, then both of them would enumerate okay. Alan Stern