Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754397Ab0KCKlY (ORCPT ); Wed, 3 Nov 2010 06:41:24 -0400 Received: from mga09.intel.com ([134.134.136.24]:10634 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754197Ab0KCKlV (ORCPT ); Wed, 3 Nov 2010 06:41:21 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.58,288,1286175600"; d="scan'208";a="569917422" Date: Wed, 3 Nov 2010 09:44:52 +0000 From: Alan Cox To: Greg KH Cc: samu.p.onkalo@nokia.com, ext Henrique de Moraes Holschuh , Alan Cox , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: Re: sysfs and power management Message-ID: <20101103094452.0cfae4ec@linux.intel.com> In-Reply-To: <20101101180740.GA17148@suse.de> 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> <20101101165701.2fc30368@linux.intel.com> <20101101180740.GA17148@suse.de> 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 Content-Length: 1404 Lines: 35 On Mon, 1 Nov 2010 11:07:40 -0700 Greg KH wrote: > On Mon, Nov 01, 2010 at 04:57:01PM +0000, Alan Cox wrote: > > > 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 ! > > I think we need to revisit this issue again, before iio is merged to > the main kernel tree. I've been totally ignoring the iio user/kernel > api at the moment, waiting for things to settle down there Actually I think there is another way to do it cleanly Keep a flag per device (or per runtime pm struct of device) And on the open/close do if (runtime_pm on device && device has SYSFS_PM set) pm_runtime_foo so that devices that need to be powered up to handle sysfs requests can set a single flag and just work. -- 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/