Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932396Ab1CWKx0 (ORCPT ); Wed, 23 Mar 2011 06:53:26 -0400 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:50455 "EHLO opensource2.wolfsonmicro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755882Ab1CWKxY (ORCPT ); Wed, 23 Mar 2011 06:53:24 -0400 Date: Wed, 23 Mar 2011 10:53:35 +0000 From: Mark Brown To: Alan Cox Cc: Nicolas Pitre , Benjamin Herrenschmidt , andy.green@linaro.org, Jaswinder Singh , Linux USB list , lkml , arnd@arndb.de, roger.quadros@nokia.com, greg@kroah.com, grant.likely@secretlab.ca Subject: Re: RFC: Platform data for onboard USB assets Message-ID: <20110323105335.GB778@opensource.wolfsonmicro.com> References: <4D79F068.2080009@linaro.org> <1300828125.2402.300.camel@pasglop> <4D8924B6.8040403@linaro.org> <1300842219.2402.309.camel@pasglop> <1300850595.2402.320.camel@pasglop> <20110323093847.55e9dbba@lxorguk.ukuu.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110323093847.55e9dbba@lxorguk.ukuu.org.uk> X-Cookie: Give him an evasive answer. User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1673 Lines: 31 On Wed, Mar 23, 2011 at 09:38:47AM +0000, Alan Cox wrote: > > Generally speaking, this wouldn't make sense. but this is a case where > > a generically probed device happens to be used in a very specific > > hardware design with its own quirks. in that very particular case then > > it certainly makes some sense. > If it's a very specific hardware design it can do its own very specific > internal private kernel patch, or little config app in user space. There > isn't a valid reason to inflict that complexity on the other 99.999999% > of users. Just to be clear this sort of stuff is not, in general, a particularly obscure problem for embedded systems. General good practice in hardware design is to remove components to achieve cost savings and improvements in manufacturability and things like configuration SEPROMs tend to be among the first things to go. Vendors producing reference boards for these markets will tend go for the cost downs on such devices even if the volumes are relatively low to ensure that their reference designs are directly usable in end projects, and reference designs tend to be disproportionately visible to people working with the kernel. In the specific case of MACs and device names for network adaptors we have userspace solutions which are obscuring the discussion but there are other things which get configured this way which one would usually expect to be handled in kernel. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/