From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2189EC433E1 for ; Thu, 28 May 2020 13:43:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F314820814 for ; Thu, 28 May 2020 13:43:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590673429; bh=Wp2FVjSuQdQM5nY27/MBV/jRvPYPLJEl3U9GGXuCNz8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=xJSo1ZzbJZOckfSvD45yluAIDBPrbFiUfqEoImm8HD7LZf/SVUSw7aaMy2mCwENnW jG7fYxmAJQd+R/CYhVJasHiAyKTK/e81NUR0sstrLxYtX+2JxDAL12+NYguKvKebtW L1+OFsSfykQ9Jure6/qwD4gDS9z2qa1Hb4lgLg5g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390531AbgE1Nnr (ORCPT ); Thu, 28 May 2020 09:43:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:45276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390468AbgE1Nnn (ORCPT ); Thu, 28 May 2020 09:43:43 -0400 Received: from localhost (fw-tnat.cambridge.arm.com [217.140.96.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4D30820814; Thu, 28 May 2020 13:43:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590673422; bh=Wp2FVjSuQdQM5nY27/MBV/jRvPYPLJEl3U9GGXuCNz8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KL6i5+zxr7qdEUS+an9gMNhOV6YmeiVg9QCnDHeRvlTgyPT3L9oUh/ULiwgUwqC2H CtIr9Q4vsabzxAkCFhJ6G+dhN7TeXGNpUbQvjENrCL8VsEA7cIJ8DjkATdZcByN1S5 FVm4wRNC/0Gsl38YMGjH65aDyWyjEgVQXd7AzKGM= Date: Thu, 28 May 2020 14:43:38 +0100 From: Mark Brown To: Marek Szyprowski Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Dmitry Osipenko , Liam Girdwood , Lucas Stach , Bartlomiej Zolnierkiewicz , Krzysztof Kozlowski , Viresh Kumar , peron.clem@gmail.com, Nishanth Menon , Stephen Boyd , Vincent Guittot , Rafael Wysocki , linux-samsung-soc@vger.kernel.org, Chanwoo Choi Subject: Re: [PATCH] regulator: do not balance regulators without constraints Message-ID: <20200528134338.GD3606@sirena.org.uk> References: <20200528131130.17984-1-m.szyprowski@samsung.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="+B+y8wtTXqdUj1xM" Content-Disposition: inline In-Reply-To: <20200528131130.17984-1-m.szyprowski@samsung.com> X-Cookie: Small is beautiful. User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --+B+y8wtTXqdUj1xM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, May 28, 2020 at 03:11:30PM +0200, Marek Szyprowski wrote: > Balancing coupled regulators must wait until the clients for all of the > coupled regualtors set their constraints, otherwise the balancing code > might change the voltage of the not-yet-constrained regulator to the > value below the bootloader-configured operation point, what might cause a > system crash. This forces every supply to have something which explicitly manages voltages which means that if one of the coupled supplies doesn't really care about the voltage (perhaps doesn't even have any explicit consumers) and just needs to be within a certain range of another supply then it'll end up restricting things needlessly. Saravana was trying to do some stuff with sync_state() which might be interesting here although I have concerns with that approach too: https://lore.kernel.org/lkml/20200527074057.246606-1-saravanak@google.com/ --+B+y8wtTXqdUj1xM Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl7PwAkACgkQJNaLcl1U h9Cwxwf+OSNkA77PUJZjj12IQJX7dCNdc8t8C/rK9BDvMjxY2PfFPsPlffbc0g5B pvA8cYyRD61MXZHFMQMcTz/padm+6CkIqNqdx3KYzBqjCe0fLhHPEzvmS0ha5rIJ QWjf6ItLBSBriLcqZxGaAfFa5wljpxsChd4rr2qO8+ye4BiAkfBP25XP2b33JFYI tJarx/8e2nvdZcQWao8WTzVcfEXoQZjYuD6OeZGME34cY+9F6MgGaPHqQbnhggC1 0HB0AWoOb/NeGCNCB8qa5k3qClZY2UzTXSz7/qr+cprSrakjdKyBlW7PBOkOAYYc fJiKt3aeBIihleWiAyfBXrRfHlg89A== =rsUY -----END PGP SIGNATURE----- --+B+y8wtTXqdUj1xM--