From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752631Ab0KARxI (ORCPT ); Mon, 1 Nov 2010 13:53:08 -0400 Received: from mga14.intel.com ([143.182.124.37]:44973 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751662Ab0KARxH (ORCPT ); Mon, 1 Nov 2010 13:53:07 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.58,275,1286175600"; d="scan'208";a="343147752" Date: Mon, 1 Nov 2010 16:57:01 +0000 From: Alan Cox To: samu.p.onkalo@nokia.com Cc: ext Greg KH , ext Henrique de Moraes Holschuh , Alan Cox , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: Re: sysfs and power management Message-ID: <20101101165701.2fc30368@linux.intel.com> In-Reply-To: <1288608087.26073.6.camel@4fid08082> References: <1288177143.12206.22.camel@4fid08082> <20101027124816.7087436a@linux.intel.com> <62697B07E9803846BC582181BD6FB6B836EB2994F4@NOK-EUMSG-02.mgdnok.nokia.com> <20101027152809.39701917@lxorguk.ukuu.org.uk> <20101029195039.GA26401@suse.de> <20101030140047.GA24464@khazad-dum.debian.net> <1288526275.2313.14.camel@noppispoppis.nmp.nokia.com> <20101031142539.GA25480@suse.de> <1288608087.26073.6.camel@4fid08082> Organization: Intel X-Mailer: Claws Mail 3.7.5 (GTK+ 2.18.9; x86_64-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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I took a look to that. It seems that iio is more or less sysfs based. > There are ring buffers and event device which are chardev based > but still the data outside ring buffer and the control is sysfs based. IIO is sysfs dependant, heavyweight and makes no sense for some of the sysfs based drivers. IIO is also staging based and Linus already threw out the last attempt to unify these drivers sanely with an ALS layer - which was smaller, cleaner and better ! > By getting open and close from sysfs would be nice from the driver > point of view. However, I understand that this is just overhead for > majority of the cases. The alternative really is to end up with a parallel 'not quite sysfs' which is sysfs + open/close. My feeling is its cleaner to have a hook at the per device level (so we don't bloat the sysfs nodes at all) than have two copies of sysfs. Alan