From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 8 Nov 2001 17:24:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 8 Nov 2001 17:24:30 -0500 Received: from cpe-24-221-186-48.ca.sprintbbd.net ([24.221.186.48]:31241 "HELO jose.vato.org") by vger.kernel.org with SMTP id ; Thu, 8 Nov 2001 17:24:16 -0500 From: "Tim Pepper" Date: Thu, 8 Nov 2001 14:24:12 -0800 To: linux-kernel@vger.kernel.org Subject: Big USB speed difference when compiled as module (was Re: speed difference between using hard-linked and modular drives?) Message-ID: <20011108142412.A19451@vato.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu 08 Nov at 17:01:24 +0100 roy@karlsbakk.net done said: > > Are there any speed difference between hard-linked device drivers and > their modular counterparts? I've been wondering this as well. I've got a curious situation: With usbcore and the uhci driver compiled into the kernel I can initiate transfers to a usb device I have (Creative Nomad Jukebox) at what I'm eyeballing to be near the 12Mbps USB speed. These tranfers always fail. With both drivers compiled as modules the transfers are over an order of magnitude slower, not even appearing to reach the 1.5Mbps USB speed, but they succeed. I haven't had a chance to try to figure out what's going on for sure. It's been a little while since I was playing with this but I believe I saw the same thing with the usb-uhci driver as well but it didn't seem to like talking to the Nomad regardless of it being compiled as a module or not. This was with the 2.4.13 kernel. I can provide more details upon request. BTW: is there a way to do USB sniffing in software in linux? I'd imagine it's possible, but just can't find anything that does... Tim