From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932289AbaIIM1K (ORCPT ); Tue, 9 Sep 2014 08:27:10 -0400 Received: from mail-we0-f169.google.com ([74.125.82.169]:59210 "EHLO mail-we0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752908AbaIIM1I (ORCPT ); Tue, 9 Sep 2014 08:27:08 -0400 From: Jean-Michel Hautbois To: linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org Cc: tgih.jun@samsung.com, ulf.hansson@linaro.org, chris@printf.net, Jean-Michel Hautbois Subject: [PATCH] mmc: Add delay between CMD6 and CMD13 for Sandisk eMMC cards Date: Tue, 9 Sep 2014 14:26:54 +0200 Message-Id: <1410265614-3275-1-git-send-email-jean-michel.hautbois@vodalys.com> X-Mailer: git-send-email 2.0.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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); + } + /* * CRC errors shall only be ignored in cases were CMD13 is used to poll * to detect busy completion. -- 2.0.4