From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266364AbUAOAY0 (ORCPT ); Wed, 14 Jan 2004 19:24:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266363AbUAOAYZ (ORCPT ); Wed, 14 Jan 2004 19:24:25 -0500 Received: from mail.kroah.org ([65.200.24.183]:7068 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S266360AbUAOAYU (ORCPT ); Wed, 14 Jan 2004 19:24:20 -0500 Date: Wed, 14 Jan 2004 16:23:34 -0800 From: Greg KH To: George Anzinger Cc: Matt Mackall , "Amit S. Kale" , Andrew Morton , jim.houston@comcast.net, discuss@x86-64.org, ak@suse.de, shivaram.upadhyayula@wipro.com, lkml , Pavel Machek Subject: Re: [discuss] Re: kgdb for x86_64 2.6 kernels Message-ID: <20040115002334.GC10153@kroah.com> References: <000e01c3d476$2ebe03a0$4008720a@shivram.wipro.com> <200401101611.53510.amitkale@emsyssoft.com> <400237F0.9020407@mvista.com> <200401122020.08578.amitkale@emsyssoft.com> <40046296.1050702@mvista.com> <20040114063155.GF28521@waste.org> <4005A03A.40409@mvista.com> <20040114232631.GB9983@kroah.com> <4005D8A5.3010002@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4005D8A5.3010002@mvista.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 14, 2004 at 04:02:45PM -0800, George Anzinger wrote: > Greg KH wrote: > >On Wed, Jan 14, 2004 at 12:02:02PM -0800, George Anzinger wrote: > > > >>Right. I had hoped that we might one day be able to use the USB and I am > >>sure there are others. > > > > > >Raw USB? Or some kind of USB to serial device? > > > >Remember, USB needs interrupts to work, see the kdb patches for the mess > >that people have tried to go through to send usb data without interrupts > >(doesn't really work...) > > I gave up on USB when I asked the following questions: > 1. How many different HW USB master devices need to be supported (i.e. > appear on your normal line of MBs)? (answer, too many) There are only 3, UHCI, OHCI, and EHCI. You can forget about EHCI, as all EHCI controllers contain either a UHCI or OHCI controller embedded in them (EHCI only handles the USB2 high speed data.) So you really only have to handle 2. > 2. Can I isolate a USB port from the kernel so that it does not even know > it is there? (answer: NO) Sorry, this is correct. Unless you want to take over the whole pci device that the USB controller is on. That's a possiblity you might want to look into. thanks, greg k-h