Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752171Ab0LIFY2 (ORCPT ); Thu, 9 Dec 2010 00:24:28 -0500 Received: from mail-wy0-f174.google.com ([74.125.82.174]:62750 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751229Ab0LIFY1 convert rfc822-to-8bit (ORCPT ); Thu, 9 Dec 2010 00:24:27 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=WOB0Ljdt1BhjJFuGXGs8SdQuSLcRyWL00P/VayRBXzfILRz6G5NvULbt8AVRd0lPsy Ek9rmrhEQj/D9gNMBF+xlTP2SbVaSlUwpxMQtuKRdqR14Vq5KG54f9MuSkHJBE+jHai9 dpgCA1KPWgfZ9Y9v+cHx5o1UljHDMin75RwY0= MIME-Version: 1.0 In-Reply-To: <20101201124900.GB5421@intel.com> References: <20101201124900.GB5421@intel.com> Date: Thu, 9 Dec 2010 14:24:25 +0900 X-Google-Sender-Auth: QApmOCNVj7pgHPoTXHfGCfWofHA Message-ID: Subject: Re: [PATCH v4 1/4]enable HW reset capbility From: Kyungmin Park To: Chuanxiao Dong Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, cjb@laptop.org, arjan@linux.intel.com, alan@linux.intel.com, akpm@linux-foundation.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: 4295 Lines: 111 On Wed, Dec 1, 2010 at 9:49 PM, Chuanxiao Dong wrote: > From d3be0b4fe8e8a40294830dfd8d0543d1e957fd29 Mon Sep 17 00:00:00 2001 > From: Chuanxiao Dong > Date: Wed, 1 Dec 2010 19:14:02 +0800 > Subject: [PATCH 1/4] enable HW reset caps of MMC card if card supports > > HW reset capbility enable bit is byte 162 in card EXT_CSD > register, only version4.4 card or later can support to enable > this feature. > > HW reset feature can be used to reset eMMC card when occures > timeout errors during read/write/erase. > > Signed-off-by: Chuanxiao Dong > --- > ?drivers/mmc/core/mmc.c ? | ? 29 +++++++++++++++++++++++++++++ > ?include/linux/mmc/card.h | ? ?1 + > ?include/linux/mmc/mmc.h ?| ? ?1 + > ?3 files changed, 31 insertions(+), 0 deletions(-) > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > index 77f93c3..85cc7f6 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -310,6 +310,10 @@ static int mmc_read_ext_csd(struct mmc_card *card) > ? ? ? ? ? ? ? ? ? ? ? ?ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT]; > ? ? ? ? ? ? ? ?card->ext_csd.trim_timeout = 300 * > ? ? ? ? ? ? ? ? ? ? ? ?ext_csd[EXT_CSD_TRIM_MULT]; > + ? ? ? ? ? ? ? /* > + ? ? ? ? ? ? ? ?* check Hardware reset cap Check hardware. > + ? ? ? ? ? ? ? ?*/ > + ? ? ? ? ? ? ? card->ext_csd.rst = ext_csd[EXT_CSD_RST]; > ? ? ? ?} > > ? ? ? ?if (ext_csd[EXT_CSD_ERASED_MEM_CONT]) > @@ -484,6 +488,31 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, > ? ? ? ?} > > ? ? ? ?/* > + ? ? ? ?* eMMC4.4 version card has HW reset capbility. capability. > + ? ? ? ?* Enable this feature here: > + ? ? ? ?* RST_N_FUNCTION register is W/R, one time programmable Use RST_n_FUNCTION as spec. > + ? ? ? ?* or readable. > + ? ? ? ?* So need to enable this register only once after power on > + ? ? ? ?*/ > + ? ? ? if (card->csd.mmca_vsn >= CSD_SPEC_VER_4 && > + ? ? ? ? ? ? ? ? ? ? ? card->ext_csd.rev >= 4 && it should be card->ext_csd.rev >= 5 since 4 is obsolete. Thank you, Kyungmin Park > + ? ? ? ? ? ? ? ? ? ? ? card->ext_csd.rst == 0) { > + ? ? ? ? ? ? ? err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? EXT_CSD_RST, 1); > + > + ? ? ? ? ? ? ? if (err && err != -EBADMSG) > + ? ? ? ? ? ? ? ? ? ? ? goto free_card; > + > + ? ? ? ? ? ? ? if (err) { > + ? ? ? ? ? ? ? ? ? ? ? printk(KERN_WARNING "%s: switch to rst enable " > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?"failed %d\n", > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?mmc_hostname(card->host), err); > + ? ? ? ? ? ? ? ? ? ? ? err = 0; > + ? ? ? ? ? ? ? } else > + ? ? ? ? ? ? ? ? ? ? ? card->ext_csd.rst = 1; > + ? ? ? } > + > + ? ? ? /* > ? ? ? ? * Activate high speed (if supported) > ? ? ? ? */ > ? ? ? ?if ((card->ext_csd.hs_max_dtr != 0) && > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index 8ce0827..ebee676 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -54,6 +54,7 @@ struct mmc_ext_csd { > ? ? ? ?unsigned int ? ? ? ? ? ?sec_trim_mult; ?/* Secure trim multiplier ?*/ > ? ? ? ?unsigned int ? ? ? ? ? ?sec_erase_mult; /* Secure erase multiplier */ > ? ? ? ?unsigned int ? ? ? ? ? ?trim_timeout; ? ? ? ? ? /* In milliseconds */ > + ? ? ? unsigned int ? ? ? ? ? ?rst; /* hardware reset enable bit */ > ?}; > > ?struct sd_scr { > diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h > index 956fbd8..b7ab0da 100644 > --- a/include/linux/mmc/mmc.h > +++ b/include/linux/mmc/mmc.h > @@ -251,6 +251,7 @@ struct _mmc_csd { > ?* EXT_CSD fields > ?*/ > > +#define EXT_CSD_RST ? ? ? ? ? ?162 ? ? /* onetime programmable R/W */ > ?#define EXT_CSD_ERASE_GROUP_DEF ? ? ? ? ? ? ? ?175 ? ? /* R/W */ > ?#define EXT_CSD_ERASED_MEM_CONT ? ? ? ? ? ? ? ?181 ? ? /* RO */ > ?#define EXT_CSD_BUS_WIDTH ? ? ? ? ? ? ?183 ? ? /* R/W */ > -- > 1.6.6.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at ?http://vger.kernel.org/majordomo-info.html > -- 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/