Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759947AbYAKGZe (ORCPT ); Fri, 11 Jan 2008 01:25:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759455AbYAKGZF (ORCPT ); Fri, 11 Jan 2008 01:25:05 -0500 Received: from ro-out-1112.google.com ([72.14.202.182]:52840 "EHLO ro-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759119AbYAKGZC (ORCPT ); Fri, 11 Jan 2008 01:25:02 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=q/LkHjR4ecWtmtgZmZ6kePhFfvG3utsx58LJz+1FQe97DDngQnOT4zOfx4ynz0vlMfu4vaAnrqPaIpxRYl4WJn18/+TKrEmFlWHQa+fGqUvay7LAgkovTEMigFvujsxwb/yVxqJbIbsFlFps6Od9ly8zcQRqXJcCU9WhxhqxMxQ= Message-ID: <8bd0f97a0801102225q69b56703gaffbc85a31390b4e@mail.gmail.com> Date: Fri, 11 Jan 2008 01:25:01 -0500 From: "Mike Frysinger" To: "Bryan Wu" Subject: Re: [patch] split MMC_CAP_4_BIT_DATA Cc: "Pierre Ossman" , "Cai, Cliff" , linux-kernel@vger.kernel.org In-Reply-To: <386072610801102217u1739d7d7v497e73a38aa876c2@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <386072610801081832w2befcbafwe9215067f022ed5d@mail.gmail.com> <0F1B54C89D5F954D8535DB252AF412FA014FAD4A@chinexm1.ad.analog.com> <20080109082325.212ec90d@poseidon.drzeus.cx> <386072610801090845r14510fb8tbcca76d605458a96@mail.gmail.com> <20080110095428.3b93fd18@poseidon.drzeus.cx> <386072610801100122n52339488ke2b8724c390be765@mail.gmail.com> <20080110125748.416ad0c5@poseidon.drzeus.cx> <386072610801102217u1739d7d7v497e73a38aa876c2@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2070 Lines: 44 On Jan 11, 2008 1:17 AM, Bryan Wu wrote: > On Jan 10, 2008 7:57 PM, Pierre Ossman wrote: > > On Thu, 10 Jan 2008 17:22:55 +0800 > > "Bryan Wu" wrote: > > > > > > > > At page 4-3 of ADSP-BF54x Blackfin(R) Processor Peripheral Hardware > > > Reference, there is a table which guide us the SDH controller does not > > > support 4-bit mode MMC card. Please found the table picture in the > > > attachment or get the document at: > > > http://www.analog.com/UploadedFiles/Associated_Docs/61460151169789ADSP_BF54x_Blackfin_Processor_Peripheral_Hardware_Reference.pdf > > > > > > > Ok, but this just means the controller wasn't designed with 4-bit MMC in mind. As several other "SD-only" controller have been tested with modern MMC cards without a problem, this is not sufficient to explain any problem. > > > > This should be some HW design issue and BF54x including SDH controller > is in mass production. > There is no chance to change the silicon, we just wanna use software > driver to workaround this issue. > So Mike's patch is here. > > > > > > > Thanks, actually we are not yet convinced by our hardware designer > > > why BF54x SDH does not support 4-bit MMC. > > > > > > > Please keep me informed on how it progresses. I'd like an at least plausible explanation, preferably also some empirical data, before I'm ready to accept Mike's patch. > > > > We were told this is an hardware design issue, so please help us to > workaround it in software side with Mike's patch. > And how do you think my suggestion to Mike's patch, > #define MMC_CAP_4_BIT_DATA ( MMC_CAP_SD_4_BIT_DATA | MMC_CAP_MMC_4_BIT_DATA) > Then no need to change other MMC host drivers i can send an updated patch as needed. i think Bryan's suggestion here is a good one. -mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/