From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755452AbYAIDa1 (ORCPT ); Tue, 8 Jan 2008 22:30:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753010AbYAIDaN (ORCPT ); Tue, 8 Jan 2008 22:30:13 -0500 Received: from nwd2mail11.analog.com ([137.71.25.57]:27412 "EHLO nwd2mail11.analog.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752901AbYAIDaL convert rfc822-to-8bit (ORCPT ); Tue, 8 Jan 2008 22:30:11 -0500 X-Greylist: delayed 582 seconds by postgrey-1.27 at vger.kernel.org; Tue, 08 Jan 2008 22:30:11 EST X-IronPort-AV: E=Sophos;i="4.24,260,1196658000"; d="scan'208";a="46426565" X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: [patch] split MMC_CAP_4_BIT_DATA Date: Wed, 9 Jan 2008 11:21:40 +0800 Message-ID: <0F1B54C89D5F954D8535DB252AF412FA014FAD4A@chinexm1.ad.analog.com> In-Reply-To: <386072610801081832w2befcbafwe9215067f022ed5d@mail.gmail.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [patch] split MMC_CAP_4_BIT_DATA Thread-Index: AchSZ+6XIxawlxXpT16EulmuksOd2wAAoKwA From: "Cai, Cliff" To: "Pierre Ossman" Cc: "Mike Frysinger" , X-OriginalArrivalTime: 09 Jan 2008 03:20:26.0930 (UTC) FILETIME=[9460A120:01C8526E] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi,all I'd like to say something about this issue. Currently,the blackfin on chip SD host ONLY support 1-bit MMC while support 1-bit/4-bit SD/SDIO. And we want our driver to support both 1-bit MMC and 4-bit SD/SDIO.but the current MMC driver framework Only allow us to set one kind of bus width,either 1-bit or 4-bit.So in order to meet our case,we need more flexible mechanism To inform the upper commom driver to know our situation. Cliff -----Original Message----- From: Bryan Wu [mailto:cooloney.lkml@gmail.com] Sent: Wednesday, January 09, 2008 10:33 AM To: Pierre Ossman; cliff.cai@analog.com Cc: Mike Frysinger; linux-kernel@vger.kernel.org Subject: Re: [patch] split MMC_CAP_4_BIT_DATA On Jan 9, 2008 4:49 AM, Pierre Ossman wrote: > On Tue, 8 Jan 2008 14:40:49 -0500 > Mike Frysinger wrote: > > > > > i dont understand what's confusing. the Blackfin on chip host > > controller only supports 1-bit MMC, but it supports 4-bit SD/SDIO. > > this is a fact. while it may be a stupid decision, it is what it > > is, and i need the framework made more flexible in order to get the > > Blackfin driver merged cleanly. we do software for hardware, we dont do hardware. > > Well, since I've seen no _hardware_ differences between 4-bit MMC and 4-bit SD, "support" in this case must me "vendor will guarantee it works". And that is not the kind of "support" that needs a distinction in the code. > > So, again, if you feel that there is a hardware difference between 4-bit MMC and 4-bit SD then please elaborate as it is my understanding that they are identical. > As Mike said, the reason split this flag is because Blackfin on-chip SDIO controller's limitation. Cliff is working on it for a long time, so I dropped him in. Hope he can clarify the confusing things. Thanks -Bryan Wu