Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755412AbcCXKZn (ORCPT ); Thu, 24 Mar 2016 06:25:43 -0400 Received: from mail-ob0-f194.google.com ([209.85.214.194]:36651 "EHLO mail-ob0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755161AbcCXKZg (ORCPT ); Thu, 24 Mar 2016 06:25:36 -0400 MIME-Version: 1.0 In-Reply-To: <20160324095332.GS2566@sirena.org.uk> References: <1458807125-13580-1-git-send-email-k.kozlowski@samsung.com> <20160324095332.GS2566@sirena.org.uk> Date: Thu, 24 Mar 2016 19:25:35 +0900 X-Google-Sender-Auth: qe305mAVU_VXSP3WrgVQWOI-yjY Message-ID: Subject: Re: [PATCH] ARM: dts: exynos: Fix invalid maximum voltage for buck9 supplying SD card From: Krzysztof Kozlowski To: Mark Brown Cc: Kukjin Kim , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, Ulf Hansson , Ivaylo Dimitrov Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1300 Lines: 28 On Thu, Mar 24, 2016 at 6:53 PM, Mark Brown wrote: > On Thu, Mar 24, 2016 at 05:12:05PM +0900, Krzysztof Kozlowski wrote: > >> buck9_reg: BUCK9 { >> regulator-name = "vdd_2.8v_ldo"; >> regulator-min-microvolt = <3000000>; >> - regulator-max-microvolt = <3750000>; >> + regulator-max-microvolt = <3755000>; >> regulator-always-on; >> regulator-boot-on; >> }; > > Why does this regulator even have voltage constraints configured? Is > there any intention that it should ever be varied at runtime? Good question. I was also wondering that, if tetting it by 5 mV lower causes failure, then the constraints are actually fixed at 3.755 V. I do not know the answer. Boards schematics do not specify the requirement here, datasheet for PMIC says default value of 3.4V. Heh, maybe the regulator driver is missing proper starting value for 'vsel' (datasheet says values in register start from 0x40 -> 3 V). Something looks wrong here... I'll look at it after weekend. For now I applied my patch to the for-next, so the next should be fixed. Best regards, Krzysztof