> -----Original Message----- > From: kyungmin78@xxxxxxxxx [mailto:kyungmin78@xxxxxxxxx] On Behalf Of > Kyungmin Park > Sent: Thursday, December 09, 2010 1:24 PM > To: Dong, Chuanxiao > Cc: linux-mmc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; cjb@xxxxxxxxxx; > arjan@xxxxxxxxxxxxxxx; alan@xxxxxxxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH v4 1/4]enable HW reset capbility > > On Wed, Dec 1, 2010 at 9:49 PM, Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx> > wrote: > > From d3be0b4fe8e8a40294830dfd8d0543d1e957fd29 Mon Sep 17 00:00:00 2001 > > From: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx> > > 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 <chuanxiao.dong@xxxxxxxxx> > > --- > > 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= 5 since 4 is obsolete.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 Thanks, Park. I will fix this. And by the way, I noticed mmc_read_ext_csd function also used card->ext_csd.rev >=4. Is there some other reason for this kind of using? Or it is just because at that time the value 4 has not be obsolete yet....? Thanks. Chuanxiao > > + 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@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
