From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750770AbVH1Trz (ORCPT ); Sun, 28 Aug 2005 15:47:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750772AbVH1Trz (ORCPT ); Sun, 28 Aug 2005 15:47:55 -0400 Received: from ylpvm12-ext.prodigy.net ([207.115.57.43]:30401 "EHLO ylpvm12.prodigy.net") by vger.kernel.org with ESMTP id S1750770AbVH1Trz (ORCPT ); Sun, 28 Aug 2005 15:47:55 -0400 X-ORBL: [69.107.75.50] From: David Brownell To: Pete Zaitcev Subject: Re: [linux-usb-devel] Re: USB EHCI Problem with Low Speed Date: Sun, 28 Aug 2005 12:47:42 -0700 User-Agent: KMail/1.7.1 Cc: dio@qwasartech.com, linux-kernel@vger.kernel.org, linux-usb-devel@lists.sourceforge.net MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200508281247.42776.david-b@pacbell.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > http://marc.theaimsgroup.com/?l=linux-usb-devel&m=112439094723976&w=2 Yes please ... these issues do seem to be intermittent and hardware-specific, so we'd like to know if relaxed enumeration timings work better for the folk who have these problems. > Yes, Dominik, please do. The TT was a poor guess, because IIRC 2.6.8 > did not have the support for TT, so it could not get it wrong. Actually every EHCI version from kernel.org has always supported TTs; I didn't submit it until full and low speed devices would enumerate, an I could use USB keyboards and mice. The reason it's a poor guess is that TT support has nothing to do with this level of problem. ;) What's changed is how smart the _periodic scheduling_ support is. The original algorithm took some major simplifying shortcuts, which reduced functionality. The latest code doesn't have very many of those shortcuts. It's accordingly a LOT more complicated. Some of the newer features need work yet (e.g. scheduling ISO OUT). - Dave