From mboxrd@z Thu Jan 1 00:00:00 1970 From: wwang Subject: Re: [PATCH v2 1/2] mmc/host/rtsx: Configure SD_CFG2 register in sd_rw_multi Date: Tue, 20 Nov 2012 10:40:14 +0800 Message-ID: <50AAED8E.4030201@realsil.com.cn> References: <00fb063304a0720f3ba9db6f79bb67263d450356.1353377266.git.wei_wang@realsil.com.cn> <87ip91f1zo.fsf@octavius.laptop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from rtits2.realtek.com ([60.250.210.242]:51546 "EHLO rtits2.realtek.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752869Ab2KTCkx (ORCPT ); Mon, 19 Nov 2012 21:40:53 -0500 In-Reply-To: <87ip91f1zo.fsf@octavius.laptop.org> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Chris Ball Cc: "sameo@linux.intel.com" , "devel@linuxdriverproject.org" , "linux-kernel@vger.kernel.org" , "linux-mmc@vger.kernel.org" , "gregkh@linuxfoundation.org" , "arnd@arndb.de" , "oakad@yahoo.com" , "bp@alien8.de" =E4=BA=8E 2012=E5=B9=B411=E6=9C=8820=E6=97=A5 10:21, Chris Ball =E5=86=99= =E9=81=93: > Hi, > > Sorry to be pedantic, but: > > On Mon, Nov 19 2012, wei_wang@realsil.com.cn wrote: >> For Realtek card reader, internal regsiter SD_CFG2 should be configu= red >> before transferring data. In the prior version, the value of this re= gister >> has been calculated, but forgotten to write back to the internal reg= ister. > With what consequences? Was the data transfer failing? Under which > circumstances? > > Thanks, > > - Chris. Hi Chris: It's about compatibility issue. The default value of SD_CFG2 is proper=20 for writing data. But for reading sequence, the timing is not good=20 enough. So in some extreme circumstance, card reader may sample the=20 response data from the card as good even if the data is wrong. And this= =20 will cause the bad consequence. Shall I modify the commit and resend the patchset again? BR, Wei WANG