From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulf Hansson Subject: Re: [PATCH v3] mmc: core: try 1.8v signling in ddr mode if host and device Date: Wed, 3 Sep 2014 09:21:27 +0200 Message-ID: References: <20140815032806.GA19745@intel.com> <17296D9F8FF2234F831FC3DF505A87A911B21734@shsmsx102.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-la0-f50.google.com ([209.85.215.50]:48436 "EHLO mail-la0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753703AbaICHV3 (ORCPT ); Wed, 3 Sep 2014 03:21:29 -0400 Received: by mail-la0-f50.google.com with SMTP id mc6so9222840lab.37 for ; Wed, 03 Sep 2014 00:21:27 -0700 (PDT) In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Jean-Michel Hautbois , "Dong, Chuanxiao" Cc: linux-mmc , "chris@printf.org" On 2 September 2014 17:31, Jean-Michel Hautbois wrote: > 2014-08-15 10:36 GMT+02:00 Dong, Chuanxiao : >> >> >>> -----Original Message----- >>> From: Ulf Hansson [mailto:ulf.hansson@linaro.org] >>> Sent: Friday, August 15, 2014 4:34 PM >>> To: Dong, Chuanxiao >>> Cc: linux-mmc; chris@printf.org >>> Subject: Re: [PATCH v3] mmc: core: try 1.8v signling in ddr mode if host and >>> device >>> >>> On 15 August 2014 05:28, Chuanxiao Dong >>> wrote: >>> > Even (e)MMC card can support 3.3v to 1.2v vccq in DDR, but not all >>> > host controller can support this, like some of the SDHCI host which >>> > connect to an eMMC device. Some of these host controller still needs >>> > to use 1.8v vccq for supporting DDR mode. >>> > >>> > So the sequence will be: >>> > if (host and device can both support 1.2v IO) >>> > use 1.2v IO; >>> > else if (host and device can both support 1.8v IO) >>> > use 1.8v IO; >>> > so if host and device can only support 3.3v IO, this is the last choice. >>> > >>> > Signed-off-by: Chuanxiao Dong >>> > Signed-off-by: Yunpeng Gao >>> >>> This looks good to me! But before I queue it for 3.18 I would appreciate if we >>> could get some help in testing this for some various platforms, that support >>> MMC DDR. >> >> Thanks a lot. BTW, this patch is already tested on Intel's platform which can support MMC DDR. > > This patch associated with vqmmc-supply and vmmc-supply in the DT is > working for me too on i.MX6. > JM Thanks! Applied for next. I took the liberty of updating the commit msg header to "mmc: core: Fix sequence for I/O voltage in DDR mode for eMMC", to get a better description of the patch. I also added a tested by tag from "JM". Please tell me if you have any concern with my changes. Kind regards Uffe