From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Kozlowski Subject: Re: Warnings for invalid VDD (sdhci-s3c) Date: Thu, 24 Mar 2016 17:42:55 +0900 Message-ID: <56F3A88F.50603@samsung.com> References: <20160324155840.50474b98@xhacker> <56F3A0B7.4050509@samsung.com> <20160324162449.29c9cf78@xhacker> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: 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 In-reply-to: <20160324162449.29c9cf78@xhacker> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Jisheng Zhang , Jaehoon Chung 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 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