Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965459AbbEMPhn (ORCPT ); Wed, 13 May 2015 11:37:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49224 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932109AbbEMPhl (ORCPT ); Wed, 13 May 2015 11:37:41 -0400 Date: Wed, 13 May 2015 08:37:40 -0700 From: Greg Kroah-Hartman To: Mark Brown Cc: Maxime Ripard , linux-kernel@vger.kernel.org, Hans de Goede , linux-spi@vger.kernel.org, Martin Sperl , Michal Suchanek Subject: Re: [PATCH] spi: Force the registration of the spidev devices Message-ID: <20150513153740.GC11677@kroah.com> References: <1431462804-30467-1-git-send-email-maxime.ripard@free-electrons.com> <20150513112604.GI3066@sirena.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150513112604.GI3066@sirena.org.uk> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1449 Lines: 32 On Wed, May 13, 2015 at 12:26:04PM +0100, Mark Brown wrote: > On Tue, May 12, 2015 at 10:33:24PM +0200, Maxime Ripard wrote: > > > While this is nicer than the DT solution because of its accurate hardware > > representation, it's still not perfect because you might not have access to the > > DT, or you might be driving a completely generic device (such as a > > microcontroller) that might be used for something else in a different > > context/board. > > Greg, you're copied on this because this seems to be a generic problem > that should perhaps be solved at a driver model level - having a way to > bind userspace access to devices that we don't otherwise have a driver > for. The subsystem could specify the UIO driver to use when no other > driver is available. That doesn't really work. I've been talking to the ACPI people about this, and the problem is "don't otherwise have a driver for" is an impossible thing to prove, as you never know when a driver is going to be loaded from userspace. You can easily bind drivers to devices today from userspace, why not just use the built-in functionality you have today if you "know" that there is no driver for this hardware. thanks, greg k-h -- 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/