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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 C4B8BC83000 for ; Tue, 28 Apr 2020 16:45:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A122A2063A for ; Tue, 28 Apr 2020 16:45:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cerno.tech header.i=@cerno.tech header.b="o/zLeawy"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="plxc6RQU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728084AbgD1Qp3 (ORCPT ); Tue, 28 Apr 2020 12:45:29 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:46579 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728022AbgD1Qp2 (ORCPT ); Tue, 28 Apr 2020 12:45:28 -0400 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id A942B5C00ED; Tue, 28 Apr 2020 12:45:27 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Tue, 28 Apr 2020 12:45:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cerno.tech; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm2; bh=S+DukyifHC2vsrH7Z+Bw4PDmgSK o2q4QVE9pfyHeloc=; b=o/zLeawy0XQRg1eQ7+597/fdWE/olg18atu9Wo9OpAV qzO2RXEsn8o6ljpJCmcHtU3aSPv8TGrdRsl3C/di7b6qEVeuxn++mSeRZJUIp8Q0 VuIaPoYH/IqD7GHhKdZWddRa4sVZR4nlrzdkOlVmTxn0n264NaAyWmqKlWUEKxCn yh/sgs4yR53G17xdi+bSLGHGBtSeqL1knY4u70hTGH1JP4nL6yv6GM2qogkN1O8c J3245jYrz9gp0GTvqjJkuTDsSgCXECue0dmOsZKFgPbXAMKTFbDlP2Tcpm76UWZj gxaONyZPXsd6+I5GDkWhO84dpc9daW0yT8vfxKAVilA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=S+Duky ifHC2vsrH7Z+Bw4PDmgSKo2q4QVE9pfyHeloc=; b=plxc6RQUfAVXjjOqju4TEk p87bIvcNyBu/Oy2aIbCzsLzgKQbl1Joq1ZXevIR3YiEbg51CvULI62q8NcFHbpK9 jaMKj9+Jjmd4LGLLje5rNhbeTT/xEfGyW9CG/wa/V7N4YSRgqEFn8OGkJmypQ9N6 0aeYbI5LaGFw8Efc/psgzzWILoJ77Gt/ITRR7VBh/m2AC4FfcSRMjWwW70Qgry8n 9rQZhr8htYwKizqSiDtXu66fCRB9F+yGtpVqEhEcEZC0bPCZEcj2iCMb0QEG1PpI trihGpHK0Ozvl7BDXAdP1Gm0lHDbM3k12EoCOtWaaVK3Qmmd8TBTj+vQ+rJB0C3Q == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduhedriedugddutdegucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehgtderredttddunecuhfhrohhmpeforgigihhm vgcutfhiphgrrhguuceomhgrgihimhgvsegtvghrnhhordhtvggthheqnecukfhppeeltd drkeelrdeikedrjeeinecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghi lhhfrhhomhepmhgrgihimhgvsegtvghrnhhordhtvggthh X-ME-Proxy: Received: from localhost (lfbn-tou-1-1502-76.w90-89.abo.wanadoo.fr [90.89.68.76]) by mail.messagingengine.com (Postfix) with ESMTPA id 125803280059; Tue, 28 Apr 2020 12:45:23 -0400 (EDT) Date: Tue, 28 Apr 2020 18:45:22 +0200 From: Maxime Ripard To: =?utf-8?B?Q2zDqW1lbnQgUMOpcm9u?= Cc: Robin Murphy , Chen-Yu Tsai , Rob Herring , devicetree , linux-kernel , linux-sunxi , Piotr Oniszczuk , linux-arm-kernel Subject: Re: [linux-sunxi] Re: [PATCH v2] arm64: dts: allwinner: h6: Use dummy regulator for Tanix TX6 Message-ID: <20200428164522.p7ypca7zwocc7alq@gilmour.lan> References: <20200428142629.8950-1-peron.clem@gmail.com> <98246e5d-ebef-bcb5-f0b8-d74b3834b835@arm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="cbn7zzdgl2fsor3b" Content-Disposition: inline In-Reply-To: Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --cbn7zzdgl2fsor3b Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 28, 2020 at 06:23:35PM +0200, Cl=E9ment P=E9ron wrote: > Hi Robin, >=20 > On Tue, 28 Apr 2020 at 17:21, Robin Murphy wrote: > > > > On 2020-04-28 3:26 pm, Cl=E9ment P=E9ron wrote: > > > Tanix TX6 has a fixed regulator. As DVFS is instructed to change > > > voltage to meet OPP table, the DVFS is not working as expected. > > > > Hmm, isn't that really a bug in the DVFS code? I guess it's just blindly > > propagating -EINVAL from the fixed regulators not implementing > > set_voltage, but AFAICS it has no real excuse not to be cleverer and > > still allow switching frequency as long as the voltage *is* high enough > > for the given OPP. I wonder how well it works if the regulator is > > programmable but shared with other consumers... that case probably can't > > be hacked around in DT. >=20 > Like you, I thought that the DVFS was clever enough to understand this > but guess not.. >=20 > Maybe they are some cases where you don't want to leave the voltage high = and > reduce the frequency. But I don't know such case. I assume the intent was to prevent a regulator driver to overshoot and end = up over-volting the CPU which would be pretty bad. I guess we could check that the voltage is in the range opp < actual voltag= e < max opp voltage ? Maxime --cbn7zzdgl2fsor3b Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXqhdogAKCRDj7w1vZxhR xf6IAP9w+DY1O6bT4B3lg/+eirUFYM1skafnWKyx1f2y49KdYQEA2gJSF//W+64e k+em/HwQHNH7fcP/zuv+U6G30n1Ocgs= =CEt2 -----END PGP SIGNATURE----- --cbn7zzdgl2fsor3b--