From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271133AbTGPVmi (ORCPT ); Wed, 16 Jul 2003 17:42:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271134AbTGPVlW (ORCPT ); Wed, 16 Jul 2003 17:41:22 -0400 Received: from mail.kroah.org ([65.200.24.183]:47077 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S271133AbTGPVlE (ORCPT ); Wed, 16 Jul 2003 17:41:04 -0400 Date: Wed, 16 Jul 2003 14:54:52 -0700 From: Greg KH To: Fredrik Tolf Cc: linux-kernel@vger.kernel.org Subject: Re: Input layer demand loading Message-ID: <20030716215452.GB2773@kroah.com> References: <200307131839.49112.fredrik@dolda2000.cjb.net> <200307161457.42862.fredrik@dolda2000.cjb.net> <20030716162639.GB7513@kroah.com> <200307162323.31836.fredrik@dolda2000.cjb.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200307162323.31836.fredrik@dolda2000.cjb.net> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 16, 2003 at 11:23:31PM +0200, Fredrik Tolf wrote: > On Wednesday 16 July 2003 18.26, Greg KH wrote: > > On Wed, Jul 16, 2003 at 02:57:42PM +0200, Fredrik Tolf wrote: > > > On Wednesday 16 July 2003 06.29, Greg KH wrote: > > > > On Mon, Jul 14, 2003 at 12:58:24PM +0200, Fredrik Tolf wrote: > > > > > If the input layer userspace interface code has been compiled as > > > > > modules, and you have a ordinary (not hotplug) device, eg. a gameport > > > > > joystick, can really the hotplug interface be used to load joydev.o > > > > > when /dev/input/js0 is opened? > > > > > > > > No, you want to load the joydev.o driver when you plug in the gameport > > > > joystick. Which will be before you open the /dev node. > > > > > > Not necessarily. When the joystick is plugged in, you want to load the > > > hardware driver modules. There's really no need for the userspace > > > interface until someone requests it. At least that's the way I see it. > > > And in any case, even if you do want to load joydev.o when the joystick > > > is plugged in, I don't see how that could be done on-demand when the > > > joystick port isn't hotplug compatible, such as is the case with > > > gameports, right? > > > > True, but then if you try to open the port, you will only get the base > > joydev.o module loaded, not the gameport driver, which is what you > > _really_ want to have loaded, right? > > Huh? Look at it this way: As it is now, if you have a non-hotplug joystick, > then you can't load anything automatically, not even the hardware drivers. Correct. > If you have demand-loading in the input layer, on the other hand, you can have > "above" directives in modules.conf (or "install" directives in modprobe.conf) > to pull in the hardware drivers along with joydev. Where do you get the hardware driver coming along with joydev? I must be missing something here... > So not only does demand-loading permit hardware drivers and userspace > interfaces independently of each other, it also provides for loading > hardware drivers on demand for non-hotplug hardware. That would be very nice, but I still don't see how your patch enables this to happen. thanks, greg k-h