From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753567AbaIOKyM (ORCPT ); Mon, 15 Sep 2014 06:54:12 -0400 Received: from mail-oi0-f47.google.com ([209.85.218.47]:49426 "EHLO mail-oi0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753158AbaIOKyL (ORCPT ); Mon, 15 Sep 2014 06:54:11 -0400 MIME-Version: 1.0 In-Reply-To: <5416C30C.6010400@samsung.com> References: <1410265614-3275-1-git-send-email-jean-michel.hautbois@vodalys.com> <54110B29.7030303@samsung.com> <5416C30C.6010400@samsung.com> From: Jean-Michel Hautbois Date: Mon, 15 Sep 2014 12:53:55 +0200 X-Google-Sender-Auth: OQXXJA3tb_xOIpu7SxEX00lJv-c Message-ID: Subject: Re: [PATCH] mmc: Add delay between CMD6 and CMD13 for Sandisk eMMC cards To: Jaehoon Chung Cc: linux-kernel , "linux-mmc@vger.kernel.org" , "tgih.jun@samsung.com" , Ulf Hansson , Chris Ball Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2014-09-15 12:44 GMT+02:00 Jaehoon Chung : > On 09/15/2014 07:08 PM, Jean-Michel Hautbois wrote: >> Hi Jaehoon, >> >>> On 09/09/2014 09:26 PM, Jean-Michel Hautbois wrote: >>>> Tested on a i.MX6 board, with Sandisk SDIN5D1-2G. >>>> Without this patch, I/O errors occur. >>>> This eMMC seems to have a different Manufacturer ID as it reads 0x45 >>>> and not 0x2 as specified in datasheet. >>> >>> I think this patch don't merge into mainline. >>> This is not solution for problem. >>> you mentioned the below comment, this is workaround. >> >> Yes >> >>>> >>>> Signed-off-by: Jean-Michel Hautbois >>>> --- >>>> drivers/mmc/core/mmc_ops.c | 9 +++++++++ >>>> 1 file changed, 9 insertions(+) >>>> >>>> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c >>>> index f51b5ba..91babaa 100644 >>>> --- a/drivers/mmc/core/mmc_ops.c >>>> +++ b/drivers/mmc/core/mmc_ops.c >>>> @@ -458,6 +458,15 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, >>>> if (!use_busy_signal) >>>> return 0; >>>> >>>> + /* WORKAROUND: for Sandisk eMMC cards, it might need certain delay >>>> + * before sending CMD13 after CMD6 >>>> + * On SDIN5D1-2G MANFID is 0x45 and not 0x2 as specified in datasheet >>>> + */ >>>> + if (card->cid.manfid == CID_MANFID_SANDISK || >>>> + card->cid.manfid == 0x45) { >>>> + msleep(1); >>>> + } >>> >>> If it's a general problem of Sandisk SDIN5D1-2G, >>> I think you need to verify this problem. And can you use the MMC_FIXUP() and QUIRK? >> >> Well, this is difficult to verify, I know that on all my SDIN5D1-2G I >> have this MANFID different from what is defined by CID_MANFID_SANDISK. >> How should I use MMC_FIXUP ? Like this ? > > I think you need to explain why delay is need. > i didn't have same card, but it might be your host controller or other problem. Well, I don't know why it is needed, this is undocumented, nothing in datasheet explains anything about this. JM