From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Ossman Subject: Re: Plea for MMC spec owners Date: Mon, 05 Jun 2006 17:57:25 +0200 Message-ID: <44845465.9020505@drzeus.cx> References: <77C7F7CB1230A74A9D19C0C111E6EDBE41C7BA@DLEE09.ent.ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <77C7F7CB1230A74A9D19C0C111E6EDBE41C7BA@DLEE09.ent.ti.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-omap-open-source-bounces@linux.omap.com Errors-To: linux-omap-open-source-bounces@linux.omap.com To: "Khasim, Syed" Cc: linux-omap-open-source@linux.omap.com List-Id: linux-omap@vger.kernel.org Khasim, Syed wrote: > Hi Pierre, > > A quick search to write_bl_partial and read_bl_partial in MMC spec gave > the following lines. > Thanks. Unfortunately, it wasn't the response I was hoping for as it isn't consistent with what we've been seeing with other MMC and SD readers. > I think you already have this pointer to SD spec, might be helpful to > others. > > http://www.sdcard.org/sd_memorycard/Simplified%20Physical%20Layer%20Spec > ification.PDF > > I have to admit, I hadn't looked that closely at that spec as it didn't cover the protocol properly. But it actually said something about this issue: 4.3.2 2GByte Card To make 2GByte card, the Maximum Block Length (READ_BL_LEN=WRITE_BL_LEN) shall be set to 1024 bytes. But Block Length set by CMD16 shall be up to 512 bytes to keep consistency with 512 bytes Maximum Block Length cards (Less than and equal 2GByte cards). Could you have a second look in the MMC spec and see if there are similar provisions? Rgds Pierre