Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751290AbVL3TQl (ORCPT ); Fri, 30 Dec 2005 14:16:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751291AbVL3TQl (ORCPT ); Fri, 30 Dec 2005 14:16:41 -0500 Received: from mustang.oldcity.dca.net ([216.158.38.3]:33668 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S1751290AbVL3TQl (ORCPT ); Fri, 30 Dec 2005 14:16:41 -0500 Subject: Re: [linux-usb-devel] Re: EHCI TT bandwidth (was Re: [PATCH] USB_BANDWIDTH documentation change) From: Lee Revell To: ddstreet@ieee.org Cc: David Brownell , linux-usb-devel@lists.sourceforge.net, Alan Stern , Bodo Eggert <7eggert@gmx.de>, linux-kernel In-Reply-To: References: <200512270857.35505.david-b@pacbell.net> <1135886739.6804.4.camel@mindpipe> Content-Type: text/plain Date: Fri, 30 Dec 2005 14:16:38 -0500 Message-Id: <1135970198.31111.18.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.5.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1452 Lines: 33 On Fri, 2005-12-30 at 14:13 -0500, Dan Streetman wrote: > On Thu, 29 Dec 2005, Lee Revell wrote: > > >How do I test them? Should this make USB audio work with > >CONFIG_USB_BANDWIDTH? > > It won't have any effect on CONFIG_USB_BANDWIDTH, as the EHCI transaction > translator scheudling code doesn't care about that config setting. This > also won't have any effect on USB 2.0 devices (e.g. a highspeed Audio > device). > > The updates will only help in the situation where there are multiple > lowpseed or fullspeed devices with periodic endpoints, all connected to > the same USB 2.0 (highspeed) hub. In that situation it's possible to > "fill up" the USB 2.0 hub's transaction translator periodic schedule with > only a few devices. The updates allow many more devices to fit in the > TT's periodic schedule. The specific number of devices depends on how > many periodic endpoints, those endpoint's poll rates, and their max packet > sizes. > OK. For some reason I though that problem was fixed, I guess it was a different issue. ALSA users previously reported that a full speed audio device didn't work at all through a high speed hub at all but that it was fixed a few months ago. Lee - 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/