From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754071AbXDZDe2 (ORCPT ); Wed, 25 Apr 2007 23:34:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754176AbXDZDe2 (ORCPT ); Wed, 25 Apr 2007 23:34:28 -0400 Received: from py-out-1112.google.com ([64.233.166.180]:13451 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754071AbXDZDe0 (ORCPT ); Wed, 25 Apr 2007 23:34:26 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=FRIq3Ih9gByeSlRTI4dmnlbAyHyufBN7XssFuJ2ZENDduL9WMo0NQK5KJA+NC1f2uic2M4ddmx61dc/hhYUTTg4p/gFnaILEIVTg3z+vfb+NrsoeD2S3wajqGkiPiVFct2+0ekJ5jtesYUMhY/VfkzajtJ5Z48xjFObdS6HZ6kg= Message-ID: Date: Thu, 26 Apr 2007 09:04:26 +0530 From: "Madhusudhan c" To: "Pierre Ossman" Subject: Re: MMCv4 support (8-bit support missing) Cc: linux-kernel@vger.kernel.org, philipl@overt.org In-Reply-To: <462D8FA2.5010609@drzeus.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <4625DAFC.4000208@drzeus.cx> <46262953.3040801@drzeus.cx> <462797EE.2050808@drzeus.cx> <462D8FA2.5010609@drzeus.cx> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi Pierre/Philip, > I've looked through the MMC 4.2 spec and I see nothing in it that even hints > that 8-bit support might be optional. So as it stands, the bus testing is still out. Okay. Its possible that my understanding was wrong in the sense that I thought bus testing procedure is mandatory to support 8-bit cards. If 8-bit is mandatory for MMC4 cards, then the changes required in the MMC core to support 8-bit might be simple. Based on host controller cap this can be handled. Philip asked me about the access to the 8-bit controller. We might not be able to provide you direct access to the hardware platform as it requires involvement of business managers and so on. But can I be of help by testing your code on our platform and leting you know the results? Regards, Madhu On 4/24/07, Pierre Ossman wrote: > Madhusudhan c wrote: > > > > Suppose a host controller is capable of suporting 8-bit and it tells > > the core that it can support 8-bit. Now the card that is plugged in > > might or might not support 8-bit based on the type of the card. There > > is no field in the ext_csd which will tell you what bus width the card > > can support. > > > > I've looked through the MMC 4.2 spec and I see nothing in it that even hints > that 8-bit support might be optional. So as it stands, the bus testing is still out. > > Rgds > Pierre > > > >