From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933276Ab2JWSlh (ORCPT ); Tue, 23 Oct 2012 14:41:37 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:56720 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932622Ab2JWSlf (ORCPT ); Tue, 23 Oct 2012 14:41:35 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Tue, 23 Oct 2012 20:41:11 +0200 From: Stefan Richter To: Peter Hurley Cc: Alan Cox , Greg Kroah-Hartman , devel@driverdev.osuosl.org, linux1394-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: Re: [PATCH 0/1] staging: Add firewire-serial driver Message-ID: <20121023204111.63e13986@stein> In-Reply-To: <1351009822.2621.158.camel@thor> References: <1350565015.23730.4.camel@thor> <20121022224505.GD24489@kroah.com> <1350959679.2621.55.camel@thor> <20121023105140.5996c3a5@pyramind.ukuu.org.uk> <1351009822.2621.158.camel@thor> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Oct 23 Peter Hurley wrote: > most controllers allow spillover into > the portion of bus cycle assigned for sync tx (which is another 4Kbytes > per 125us). All controllers do so and are expected to do so. Asynchronous traffic is not supposed to depend on a cycle master being active. > (Technical note: the actual total max for combined async > and sync tx is 6144 bytes per 125us clock) It depends on bus topology, transaction types, and more. For a single-hop S400 1394a bus (vulgo FireWire 400) I once calculated 44 MB/s bandwidth of asynchronous unified write transactions: http://marc.info/?l=linux1394-devel&m=109128028930225 That's at the physical layer; link layer and application layer performances are less than that of course. -- Stefan Richter -=====-===-- =-=- =-=== http://arcgraph.de/sr/