From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759007AbYE2U7z (ORCPT ); Thu, 29 May 2008 16:59:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753205AbYE2U7r (ORCPT ); Thu, 29 May 2008 16:59:47 -0400 Received: from accolon.hansenpartnership.com ([76.243.235.52]:39605 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753007AbYE2U7q (ORCPT ); Thu, 29 May 2008 16:59:46 -0400 Subject: Re: [Ksummit-2008-discuss] RFC: Moving firmware blobs out of the kernel. From: James Bottomley To: Yinghai Lu Cc: Matthew Wilcox , Arjan van de Ven , Greg KH , ksummit-2008-discuss@lists.linux-foundation.org, David Woodhouse , David Miller , linux-kernel@vger.kernel.org In-Reply-To: <86802c440805291355p5697c775k5f0beb8163688058@mail.gmail.com> References: <1211995212.3445.52.camel@localhost.localdomain> <20080528.225826.40264516.davem@davemloft.net> <1212041839.8888.38.camel@pasglop> <20080529124548.GC8065@mit.edu> <1212077700.26088.83.camel@shinybook.infradead.org> <20080529164745.GA21763@kroah.com> <483F1232.4010003@linux.intel.com> <20080529204736.GZ22636@parisc-linux.org> <86802c440805291355p5697c775k5f0beb8163688058@mail.gmail.com> Content-Type: text/plain Date: Thu, 29 May 2008 15:59:42 -0500 Message-Id: <1212094782.3428.48.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1 (2.22.1-2.fc9) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2008-05-29 at 13:55 -0700, Yinghai Lu wrote: > On Thu, May 29, 2008 at 1:47 PM, Matthew Wilcox wrote: > > On Thu, May 29, 2008 at 01:29:38PM -0700, Arjan van de Ven wrote: > >> I very much would like to see a kernel-firmware or something tarbal that contains > >> a copy of all relevant "freely distributable" firmware, that users can just install > >> independent of the actual kernel version (and that kbuild would just pick up somehow). > >> That way we can deal with a lot more firmware without having to pollute the kernel / kernel release process > >> (after all, the timing is different in terms of releasing) while making it easy > >> to get the lot of it. > > > > There's definitely two schools of thought on this. Sometimes firmware > > changes (or adds) an interface. If the kernel driver has to accommodate > > new and old firmware, that adds complexity, and we all know that added > > complexity means more bugs. So I can definitely see some vendors > > wanting to distribute their firmware with the kernel. > > > driver should check fw version... Drivers with built in firmware usually don't. Most don't actually have even a version string they could check. Why would they: the firmware with the driver is the right one. When I converted the aic94xx driver to go from built in firmware to externally loaded, the first thing I had to do was to give it a firmware version string in the binary. It's this type of problem that makes the conversion such a pain. James