From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 20 Dec 2002 12:14:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 20 Dec 2002 12:14:58 -0500 Received: from mta7.pltn13.pbi.net ([64.164.98.8]:41447 "EHLO mta7.pltn13.pbi.net") by vger.kernel.org with ESMTP id ; Fri, 20 Dec 2002 12:14:57 -0500 Date: Fri, 20 Dec 2002 08:42:08 -0800 From: David Brownell Subject: Re: USB 2.0 is too slow? To: linux-kernel@vger.kernel.org Message-id: <3E034860.70509@pacbell.net> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii; format=flowed Content-transfer-encoding: 7BIT X-Accept-Language: en-us, en, fr User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.9) Gecko/20020513 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Some problems I met as follows. You didn't mention what kernel or driver version you used. I'd expect more success with the latest 2.5 code, which should appear as a patch against 2.4.21pre soon. > (1)Sometimes it can copy completely in 30 seconds. 300 MB, 30 seconds ... 10 MB/sec, faster can be had; that shouldn't tax the usb2 hardware at all. But some PCI systems might not like that additional load. > Is the echi-hcd module instable or immature now? > Or the VIA USB 2.0 host controller is bad support? Some of both. It's explicitly so on 2.4 (CONFIG_EXPERIMENTAL) and has on 2.5 has recently been regaining stability. Not that long ago we switched over so usb-storage uses scatterlists to do queued I/O, stressing the driver and hardware a lot more ... the expected kinds of bugs did show up, and are being squished. And you need relatively recent drivers for the VIA support to behave, in any case. Or even Intel; there's a timeout that Intel expects to be relatively long, and current kernels have it quite short. We learned that just this week... :) - Dave