On Thu, Dec 9, 2010 at 2:40 PM, Dong, Chuanxiao <chuanxiao.dong@xxxxxxxxx> wrote: > > >> -----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= 5 since 4 is obsolete.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....? Maybe need to fix it also. And remaining patches also need to fix 'capability' typo. Thank you, Kyungmin Park > > 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 > -- 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
