From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757421Ab2DYJ6X (ORCPT ); Wed, 25 Apr 2012 05:58:23 -0400 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:34053 "EHLO opensource.wolfsonmicro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754975Ab2DYJ6W (ORCPT ); Wed, 25 Apr 2012 05:58:22 -0400 Date: Wed, 25 Apr 2012 10:58:19 +0100 From: Mark Brown To: Ulf Hansson Cc: Liam Girdwood , "linux-kernel@vger.kernel.org" , Mattias WALLIN , Jonas ABERG , Lee Jones , Jassi Brar Subject: Re: [PATCH] regulator: core: Keep boot_on regulators powered during init Message-ID: <20120425095819.GG3195@opensource.wolfsonmicro.com> References: <20120423110522.GB8318@opensource.wolfsonmicro.com> <4F95495D.4050508@stericsson.com> <20120423122555.GM8318@opensource.wolfsonmicro.com> <4F954ED6.2040201@stericsson.com> <20120423180140.GR8318@opensource.wolfsonmicro.com> <4F965FC4.7010502@stericsson.com> <20120424105603.GA12063@opensource.wolfsonmicro.com> <4F969FE8.7040500@stericsson.com> <20120425080226.GA3195@opensource.wolfsonmicro.com> <4F97C5E0.1050808@stericsson.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="4eRLI4hEmsdu6Npr" Content-Disposition: inline In-Reply-To: <4F97C5E0.1050808@stericsson.com> X-Cookie: You will be awarded some great honor. 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 --4eRLI4hEmsdu6Npr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Apr 25, 2012 at 11:37:36AM +0200, Ulf Hansson wrote: > Maybe you have convinced me now :-) I will therefore start thinking > of a patch on the mmc framework instead. I will include you if/when > I send out the patch to the mmc-list, just for reference if that is > ok with you? Yes, please - there've been some issues with the way regulators are used in MMC for a while. There's definitely some stuff that needs to be worked through here. I've also added Jassi who it just occurred to me was talking about some vaugley similar stuff relatively recently (though I'm not sure it was MMC). Jassi, the issue here is working out if an MMC device is powered at boot so we can skip probing then shutting it down cleanly. > Some final thoughts (please comment if you like): > We already have the boot_on constraint, which to me is similar to > what a new kind of "boot keep state" constraint would be. I think it > would be no more odd than what boot_on already is. Maybe not a good > argument, but still.. Yeah, the main use case for boot_on is to support things like automatic enumeration of devices - for buses where we can enumerate devices when they're plugged in we normally don't explicitly register them so if we boot with the regulator disabled we need some way of allowing the device to appear on the bus. Don't know that that actually gets much use though. It is also used by regulators which for some reason can't figure out their initial state, there's a few examples of that in mainline. --4eRLI4hEmsdu6Npr Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJPl8q0AAoJEBus8iNuMP3dAnEQAIWtGGWp78Jh8/qWGr0cCcg3 LSefOlHnWIopPdpDdPu/cXYl2pw5X3Z8LcCN/J3d20bzoB5ba6PYhkqRsaSxK45p uFXbETxMAsIT/dmFC35/bl9PZYSF2nuyR+nXJwEpi3AZpJhCc8dlt0ciyaBgU8/o T6i+u1Nnk6ZLRSFby26dFKcREU0xqI8RvgprFOr7isVKuhun04U8FLMDVsPl3c63 UtRObFp2pD0B8a3x8C7tCIS/AkEKg1W54ftegfxrdT9VuuWtBCOzIadv0QH+zy6H 7Xe5j8I8MVOpQe9s03miNDc4CvqK9qtIr7MvrN8q/WxxOk5lqxZAtmu/1Vw464UE 8pPLRk2sAXXFPlCvP4m731oIOfRfIFpMaCYGb3NEpubZiQ9K5AtQfwZgY7cZd88f wktvyrwMhOaRW8aAXuoq0mud46V3rhwWZ1w8nigF1Jy3RSXySeX085Qkiw/NVeTk ehc+ZLX9eoMQA37erZS+a69Nfn8YJ9sJ83R+iebmqqZQIcYXwNdZB0KyLt5N4Zjy 6/JyFTzYjTNhmSKvELKgYdlZmnk4OuEbHFIsCDwnUn6pFH6ZG2jpumS8Q+j7JaP+ mvGXcRodUh1N1IjGI+rwEDZKQUE1fTP1eDL+YfXqQkxeSMt6vnvP1PhFHWXHgufD TfeBd0hLa36T2K/xIF0o =boSG -----END PGP SIGNATURE----- --4eRLI4hEmsdu6Npr--