Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754313AbXFKUnH (ORCPT ); Mon, 11 Jun 2007 16:43:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752205AbXFKUmz (ORCPT ); Mon, 11 Jun 2007 16:42:55 -0400 Received: from ug-out-1314.google.com ([66.249.92.172]:28153 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919AbXFKUmy (ORCPT ); Mon, 11 Jun 2007 16:42:54 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=IkQlI/5luaBIRM6Gb5tZXfNQJE37fPu0K2V3lzg3mRFcKExITgsRWTcVnoqvocqjB18VSZsIs8geS7PTYOL4+QhfLN6bQAxI6SeI+NZpk6dan8cEkSsIkvVtYT+AUSvfR5V16o0bg09f+VLiwg6AgzNp1yCDZwU0DTqQIsQmjws= Message-ID: <466DCFD4.9080702@gmail.com> Date: Tue, 12 Jun 2007 00:42:28 +0200 From: Robert de Rooy User-Agent: Thunderbird 2.0.0.0 (Windows/20070326) MIME-Version: 1.0 To: Alan Stern CC: Jiri Kosina , Greg KH , Joel.Becker@oracle.com, USB development list , Kernel development list Subject: Re: [linux-usb-devel] ThinkPad T41 - Strange USB 2.0 behaviour References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1460 Lines: 35 Alan Stern wrote: > Okay. It's clear that you've got a hardware problem of some sort. > Hard to say what it is, but evidently the EHCI controller thinks that > the device is repeatedly being unplugged and replugged. > > Anyway, this isn't a problem of recognizing that a single device is > having problems. In fact the computer has no way of knowing that a > single device is involved; all it knows is that _something_ gets > plugged into the port and then removed. There's no way to tell if it's > the same _something_ from one iteration to the next. > > You can manually force the port to run at full speed instead of high > speed as follows: > > echo '4' >/sys/class/usb_host/usb_host4/companion > > The "companion" attribute file contains a list of ports which are > permanently set to be handled by the EHCI's companion controller. To > return to high-speed operation, use '-4' instead of '4' above. This > might or might not solve your problem -- the hardware bug might cause > the port to return automatically to high-speed regardless. > > Let me know what happens. > > Alan Stern Yes that works. I tried to plug and unplug the device repeatedly and each time it came up in full-speed mode. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/