From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756049AbXGHMXi (ORCPT ); Sun, 8 Jul 2007 08:23:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752743AbXGHMX3 (ORCPT ); Sun, 8 Jul 2007 08:23:29 -0400 Received: from 85.8.24.16.se.wasadata.net ([85.8.24.16]:50225 "EHLO smtp.drzeus.cx" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752047AbXGHMX2 (ORCPT ); Sun, 8 Jul 2007 08:23:28 -0400 Date: Sun, 8 Jul 2007 14:23:25 +0200 From: Pierre Ossman To: "Midhun Agnihotram" Cc: "Nobin Mathew" , linux-kernel@vger.kernel.org Subject: Re: platform_driver_register() ?? Message-ID: <20070708142325.479d380e@poseidon.drzeus.cx> In-Reply-To: <4dde4acb0707050221k5a73a4abt2db9e8b0f7c74ae1@mail.gmail.com> References: <4dde4acb0707030028p2c078a22jd537853f145c2518@mail.gmail.com> <8d6898730707030558o5e110b0v257ffc6350c76069@mail.gmail.com> <20070703211513.5245946b@poseidon.drzeus.cx> <4dde4acb0707050221k5a73a4abt2db9e8b0f7c74ae1@mail.gmail.com> X-Mailer: Claws Mail 2.10.0 (GTK+ 2.11.5; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 5 Jul 2007 14:51:35 +0530 "Midhun Agnihotram" wrote: > > Is it necessary that the firmware (may be bootloader) notify about > the MMC host to Linux? The kernel documentation (platform.txt) says : > > "The firmware should notify the platform bus about devices before the > legacy drivers have had a chance to load." > > Have I interpreted the above sentence correctly? > I don't know what the meaning of that sentence was supposed to be, but platform devices are everything the kernel cannot probe in a "normal" way. Usually this covers devices that cannot be probed at all, but must be listed some other way (i.e. manually). Commonly the arch and machine specific code adds the devices. The machine code is usually specific to a certain hardware, so the code "knows" which devices are present, even though it can't probe them. So to answer your question; no, the firmware doesn't have to tell Linux about the devices. Rgds -- -- Pierre Ossman Linux kernel, MMC maintainer http://www.kernel.org PulseAudio, core developer http://pulseaudio.org rdesktop, core developer http://www.rdesktop.org