Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754338AbZCKOiY (ORCPT ); Wed, 11 Mar 2009 10:38:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751923AbZCKOiP (ORCPT ); Wed, 11 Mar 2009 10:38:15 -0400 Received: from mail-fx0-f176.google.com ([209.85.220.176]:46434 "EHLO mail-fx0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751698AbZCKOiO convert rfc822-to-8bit (ORCPT ); Wed, 11 Mar 2009 10:38:14 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=A0Xwcqxxa1SZkb698SBQkGALOp+8JIpdStpeXZj7/Q/9U9qpzHItKGdJEAPTHc80+f O5uEILAHbKMmgZgXp/BwewA6Ewc7+vgXZU+T0kmEJ9+buRcDecA/PLxOV8TeVqCBDpni nzAlgmVV1KiIZo9xP5D3/nWNvFYUO/2nL/C/A= MIME-Version: 1.0 In-Reply-To: <200903111534.34340.wolfgang.mues@auerswald.de> References: <87a5b0800903110656x7000e0c8q23ceae7e87483bf7@mail.gmail.com> <200903111534.34340.wolfgang.mues@auerswald.de> Date: Wed, 11 Mar 2009 14:38:09 +0000 Message-ID: <87a5b0800903110738h508aae87y7fc462d30cc89c7f@mail.gmail.com> Subject: Re: [PATCH 7/7] mmc_spi: support for non-byte-aligned cards From: Will Newton To: =?ISO-8859-1?Q?Wolfgang_M=FCes?= Cc: Pierre Ossman , Andrew Morton , Matt Fleming , David Brownell , Mike Frysinger , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1636 Lines: 43 On Wed, Mar 11, 2009 at 2:34 PM, Wolfgang M?es wrote: > Will, > > Am Mittwoch, 11. M?rz 2009 schrieb Will Newton: >> wrote: >> > From: Wolfgang Muees >> > >> > o A very large subset of SD cards in the market send their >> > ?responses and data non-byte-aligned. So add logic to the >> > ?mmc spi driver to handle this mess. >> >> Are you sure about this? > > Yes. > >> Do you have any further references for this >> or examples of cards that exhibit this problem? > > Kingston. The 1 GByte SD card, and a 128 MByte microSD card. I have got some > reports from other mmc spi users with the same problem. Are they using the same host controller? Have you tried these cards with a different host controller? Are you clocking them particularly slow or fast? > The SD protocoll ist NOT byte-aligned. Messages are starting with a > leading "0" bit. I think some chip vendors have adapted the SPI mode from SD > mode and forgotten to do propper byte alignment. > >> Are you sure your SPI host controller is operating correctly? > > Yes. My logic probe gives the same results as my spi host controller. > For some cards, you can see the bit offset is getting larger if the > controller on the SD card is getting more and more busy... A logic probe may not display any signal integrity issues you might have. -- 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/