From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joakim Tjernlund Subject: Re: [PATCH] Revert "sdhci-of-esdhc: Support 8BIT bus width." Date: Sun, 17 May 2015 08:36:07 +0000 Message-ID: <1431851766.6782.7.camel@transmode.se> References: <1431671349-12759-1-git-send-email-haokexin@gmail.com> <1431673364.13197.10.camel@transmode.se> <1431674695.13197.14.camel@transmode.se> <20150515074254.GP8870@pek-khao-d1.corp.ad.wrs.com> <1431693634.13197.29.camel@transmode.se> <20150517050602.GB23513@pek-khao-d1.corp.ad.wrs.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from smtp.transmode.se ([31.15.61.139]:58545 "EHLO smtp.transmode.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752317AbbEQIgM convert rfc822-to-8bit (ORCPT ); Sun, 17 May 2015 04:36:12 -0400 In-Reply-To: <20150517050602.GB23513@pek-khao-d1.corp.ad.wrs.com> Content-Language: en-US Content-ID: <604DF0BC898ED04893F94872253B3A6E@transmode.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: "haokexin@gmail.com" Cc: "ulf.hansson@linaro.org" , "linux-mmc@vger.kernel.org" On Sun, 2015-05-17 at 13:06 +0800, Kevin Hao wrote: > > > > How about this one: > > > > From af6b18c056b6064424bd2ab1f9989bbadae5e701 Mon Sep 17 00:00:00 2001 > > From: Joakim Tjernlund > > Date: Mon, 20 Apr 2015 22:36:55 +0200 > > Subject: [PATCHv3] sdhci-of-esdhc: Support 8BIT bus width. > > > > esdhc_readb()/esdhc_writeb() did not adjust for 8BIT. > > Do we really need this for the 8bit bus support? There is already a specific > API for setting the bus width, this change seems unnecessary to me. That is > also why I choose to revert that patch. Did I miss something? We do, the bus API really only works well when the bus bits are in another register but the HOST_CONTROL register. The only reason 4BIT works is because its bit placement is where SDHCI expects it to be. 8BIT is not, so unless readb/writeb funktions compensate for that they will overwrite what the bus API set earlier. Atleast this is my understanding, Ulf? Didn't this patch work for you either? Jocke