Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756889AbcCXInM (ORCPT ); Thu, 24 Mar 2016 04:43:12 -0400 Received: from mailout1.w1.samsung.com ([210.118.77.11]:11144 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755124AbcCXInD (ORCPT ); Thu, 24 Mar 2016 04:43:03 -0400 X-AuditID: cbfec7f5-f792a6d000001302-4e-56f3a894c9fe Subject: Re: Warnings for invalid VDD (sdhci-s3c) To: Jisheng Zhang , Jaehoon Chung References: <20160324155840.50474b98@xhacker> <56F3A0B7.4050509@samsung.com> <20160324162449.29c9cf78@xhacker> Cc: Ulf Hansson , Adrian Hunter , ludovic.desroches@atmel.com, "Ivan T. Ivanov" , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org From: Krzysztof Kozlowski Message-id: <56F3A88F.50603@samsung.com> Date: Thu, 24 Mar 2016 17:42:55 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-version: 1.0 In-reply-to: <20160324162449.29c9cf78@xhacker> Content-type: text/plain; charset=windows-1252 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrJLMWRmVeSWpSXmKPExsVy+t/xa7pTVnwOM+i4JW1x8skaNovL82ey W9z41cZq8e74bhaL1y8MLS7vmsNmceR/P6PFjPP7mCwOzUy2OL423IHLY8GvrSwei/e8ZPK4 c20Pm8fkhReZPfq2rGL0+LxJLoAtissmJTUnsyy1SN8ugStjS2ddQTd3xbqjQQ2Mdzi6GDk5 JARMJO58Oc0KYYtJXLi3ng3EFhJYyijR/L2gi5ELyH7KKPH1+ClmkISwgKFE7/Q7jCC2iIC/ ROe/bkaIop2MEm9vnmUCSTAL/GaUeLwyA8RmEzCW2Lx8CdhUXgENicVTusBqWARUJfoXfgSL iwpESDyZe5IRokZQ4sfkeywgNqeAnsSXm3uAFnMAzdSTuH9RC2K8vMTmNW+ZJzAKzELSMQuh ahaSqgWMzKsYRVNLkwuKk9JzjfSKE3OLS/PS9ZLzczcxQiLg6w7GpcesDjEKcDAq8fDe4Poc JsSaWFZcmXuIUYKDWUmE12wxUIg3JbGyKrUoP76oNCe1+BCjNAeLkjjvzF3vQ4QE0hNLUrNT UwtSi2CyTBycUg2MC1rDj7mHRVXv2dtvuGti5PfyI9YNP5tOvg1ic/tq0Pm/8mJhS4yy/qvd J/RlU/+fcLWcm1dbI/9YfsXUmtx09cUl/9lM3/seqPM7+8766fO8uU++7fuXcG7K0fWrglpV 9zTc+6S6qV5Y2iF2oaH7z12nK5V8wi2yZ68TcFF9/ezaq0VS7xYZK7EUZyQaajEXFScCANQA 0vR8AgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1375 Lines: 44 On 24.03.2016 17:24, Jisheng Zhang wrote: > Hi, > > On Thu, 24 Mar 2016 17:09:27 +0900 Jaehoon Chung wrote: > >> Hi, >> >> On 03/24/2016 04:58 PM, Jisheng Zhang wrote: >>> Hi, >>> >>> On Thu, 24 Mar 2016 16:28:56 +0900 Krzysztof Kozlowski wrote: >>> >>>> Hi, >>>> >>>> After 918f4cbd4340 ("mmc: sdhci: restore behavior when setting VDD via >>>> external regulator") On Trats2 board I see warnings for invalid VDD >>>> value (2.8V): >>>> >>>> [ 3.119656] ------------[ cut here ]------------ >>>> [ 3.119666] WARNING: CPU: 3 PID: 90 at >>>> ../drivers/mmc/host/sdhci.c:1234 sdhci_do_set_ios+0x4cc/0x5e0 >>>> [ 3.119669] mmc0: Invalid vdd 0x10 >>> >>> Per my understanding, the wrong vdd indicates a wrong ocr, what's the voltage of >>> this host's vmmc regulator? >> >> As i know, it's fixed-voltage with gpio on trats2. It's 2.8V. >> I didn't check this entirely..need to check ocr value. >> > > I may know the reason. the vmmc is 2.8v, then mmc_regulator_get_supply() convert > the value to a ocr as 0x10. The key here is that the 2.8v is invalid in SDHCI > case and isn't accepted by current sdhci driver. Yeah, I already wrote that. It is the part of the warning and my email. Our regulator is fixed at 2.8 which is 0x10. :) > I dunno the elegant solution to handle this case, let's wait for sdhci maintainers > idea. Hmm... Best regards, Krzysztof