From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030382AbaDJLri (ORCPT ); Thu, 10 Apr 2014 07:47:38 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:38716 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030235AbaDJLrg (ORCPT ); Thu, 10 Apr 2014 07:47:36 -0400 Date: Thu, 10 Apr 2014 12:46:53 +0100 From: One Thousand Gnomes To: Mauro Carvalho Chehab Cc: shuah.kh@samsung.com, Greg KH , tj@kernel.org, rafael.j.wysocki@intel.com, linux@roeck-us.net, toshi.kani@hp.com, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, shuahkhan@gmail.com Subject: Re: [RFC PATCH 0/2] managed token devres interfaces Message-ID: <20140410124653.64aeb06d@alan.etchedpixels.co.uk> In-Reply-To: <20140410083841.488f9c43@samsung.com> References: <20140409191740.GA10748@kroah.com> <5345CD32.8010305@samsung.com> <20140410120435.4c439a8b@alan.etchedpixels.co.uk> <20140410083841.488f9c43@samsung.com> Organization: Intel Corporation X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.20; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > For example, some devices provide standard USB Audio Class, handled by > snd-usb-audio for the audio stream, while the video stream is handled > via a separate driver, like some em28xx devices. Which is what mfd is designed to handle. > There are even more complex devices that provide 3G modem, storage > and digital TV, whose USB ID changes when either the 3G modem starts > or when the digital TV firmware is loaded. But presumably you only have one driver at a time then ? > So, we need to find a way to lock some hardware resources among > different subsystems that don't share anything in common. Not sure if > mfd has the same type of problem of a non-mfd driver using another > function of the same device The MFD device provides subdevices for all the functions. That is the whole underlying concept.