From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xuebing Wang Subject: Re: /dev/mmcblk0 (or /dev/mmcblk0p1) does not exist on Freescale iMX6SL board Date: Fri, 01 May 2015 18:39:09 +0800 Message-ID: <554357CD.4030903@gmail.com> References: <5541F3CC.4090000@gmail.com> <554223C4.9030506@gmail.com> <554227C5.70004@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-qg0-f41.google.com ([209.85.192.41]:35448 "EHLO mail-qg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753664AbbEAKjP (ORCPT ); Fri, 1 May 2015 06:39:15 -0400 Received: by qgej70 with SMTP id j70so36446338qge.2 for ; Fri, 01 May 2015 03:39:14 -0700 (PDT) In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Fabio Estevam Cc: "linux-mmc@vger.kernel.org" , Shawn Guo , Sascha Hauer , Ulf Hansson , Felipe Balbi , niranjan Patil , richard Jiang On 04/30/2015 09:06 PM, Fabio Estevam wrote: >> Fabio, >> > >> >Thanks. No, I do not have access to a mx6sl-evk. But I can try to get one. >> > >> >There is no eMMC (only sd-card) on mx6sl-evk, right? > That's correct. If you need eMMC with mx6sl, then you can try imx6sl-warp. > > I have tested both boards here recently and mmc operation is working fine. Fabio, thanks. I got my eMMC working on kernel v4.0.1 by: 1) In device tree, use 8 data lines (rather than 4 lines for sdhc) 2) Force ext_csd.rev to be 4 ------------------------- diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 1d41e85..aa1ca6c 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -355,6 +355,7 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd) * are authorized, see JEDEC JESD84-B50 section B.8. */ card->ext_csd.rev = ext_csd[EXT_CSD_REV]; + card->ext_csd.rev = 4; card->ext_csd.raw_sectors[0] = ext_csd[EXT_CSD_SEC_CNT + 0]; card->ext_csd.raw_sectors[1] = ext_csd[EXT_CSD_SEC_CNT + 1]; ------------------------- eMMC on my board is Micron "MTFC4GLDDQ-4M IT", according to its datasheet, it is "JEDEC/MMC standard version 4.41-compliant (JEDEC Standard No. 84-A441)", and its "Extended CSD revision" (EXT_CSD_REV) = 5 This seems either because kernel does not handle (ext_csd == 5) correctly, or there is an firmware issue in Micron "MTFC4GLDDQ-4M IT" (in terms of JEDEC standard compliance), what do you think? -- Xuebing