| Message ID | 20101203121338.GB18655@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Dec 3, 2010 at 1:13 PM, Chuanxiao Dong <chuanxiao.dong@intel.com> wrote: > From 984adc755cf2f7966a89e510a50f085e314fe347 Mon Sep 17 00:00:00 2001 > From: Chuanxiao Dong <chuanxiao.dong@intel.com> > Date: Mon, 22 Nov 2010 16:31:12 +0800 > Subject: [PATCH 1/4] mmc: Enabled background operations feature if eMMC card supports > > Background operations is a new feature defined in eMMC4.41 standard. > Since this feature is opertional for eMMC card, so driver only enable > for those eMMC card which supports this feature > > Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> > --- > drivers/mmc/core/mmc.c | 26 ++++++++++++++++++++++++++ > include/linux/mmc/card.h | 2 ++ > include/linux/mmc/mmc.h | 3 +++ > 3 files changed, 31 insertions(+), 0 deletions(-) > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > index 77f93c3..471ed82 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -310,6 +310,14 @@ 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]; > + > + /* detect whether the eMMC card support BKOPS */ > + if (ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1) { > + card->ext_csd.bkops = 1; > + card->ext_csd.bkops_en = > + ext_csd[EXT_CSD_BKOPS_EN]; > + } > + > } > > if (ext_csd[EXT_CSD_ERASED_MEM_CONT]) > @@ -484,6 +492,24 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, > } > > /* > + * enable BKOPS if eMMC card supports. > + */ > + if (card->ext_csd.bkops) { > + if (!card->ext_csd.bkops_en) { > + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, > + EXT_CSD_BKOPS_EN, 1); Is it always wise to set BKOPS_EN to 1 if bkops is supported? BKOPS_EN=1 will enable periodic background operations. The card will somehow decide periodically when to start background operations. If BKOPS_EN=0 the background operations need to be started manually. The mmc framework could make the decision when to start background operations. Using dynamic clock control or suspend/resume may cause the periodic internal operations to be delayed since it can't run without clocking or power. Do you have any test results comparing periodic and manual bkops? On way forward is to add support for both periodic bkops and manual bkops and let the device platform_data specify what to use? Regards, Per -- 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
On Mon, May 2, 2011 at 9:53 PM, Per Forlin <per.lkml@gmail.com> wrote: > On Fri, Dec 3, 2010 at 1:13 PM, Chuanxiao Dong <chuanxiao.dong@intel.com> wrote: >> From 984adc755cf2f7966a89e510a50f085e314fe347 Mon Sep 17 00:00:00 2001 >> From: Chuanxiao Dong <chuanxiao.dong@intel.com> >> Date: Mon, 22 Nov 2010 16:31:12 +0800 >> Subject: [PATCH 1/4] mmc: Enabled background operations feature if eMMC card supports >> >> Background operations is a new feature defined in eMMC4.41 standard. >> Since this feature is opertional for eMMC card, so driver only enable >> for those eMMC card which supports this feature >> >> Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> >> --- >> drivers/mmc/core/mmc.c | 26 ++++++++++++++++++++++++++ >> include/linux/mmc/card.h | 2 ++ >> include/linux/mmc/mmc.h | 3 +++ >> 3 files changed, 31 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c >> index 77f93c3..471ed82 100644 >> --- a/drivers/mmc/core/mmc.c >> +++ b/drivers/mmc/core/mmc.c >> @@ -310,6 +310,14 @@ 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]; >> + >> + /* detect whether the eMMC card support BKOPS */ >> + if (ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1) { >> + card->ext_csd.bkops = 1; >> + card->ext_csd.bkops_en = >> + ext_csd[EXT_CSD_BKOPS_EN]; >> + } >> + >> } >> >> if (ext_csd[EXT_CSD_ERASED_MEM_CONT]) >> @@ -484,6 +492,24 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, >> } >> >> /* >> + * enable BKOPS if eMMC card supports. >> + */ >> + if (card->ext_csd.bkops) { >> + if (!card->ext_csd.bkops_en) { >> + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, >> + EXT_CSD_BKOPS_EN, 1); > Is it always wise to set BKOPS_EN to 1 if bkops is supported? > BKOPS_EN=1 will enable periodic background operations. The card will > somehow decide periodically when to start background operations. If > BKOPS_EN=0 the background operations need to be started manually. The > mmc framework could make the decision when to start background > operations. BKOP_EN=0 means act like a pre v4.41 device. No maintenance required. Thanks Bruce for pointing this out to me. > Using dynamic clock control or suspend/resume may cause the periodic > internal operations to be delayed since it can't run without clocking > or power. > Do you have any test results comparing periodic and manual bkops? > On way forward is to add support for both periodic bkops and manual > bkops and let the device platform_data specify what to use? Please discard this comment. My concern is when to fire BKOPS_START. Would it make sense to check the BKOPS_STATUS before going to sleep and start bkops even if level is only "non critical"? This would defer sleep until bkops are completed. Regards, Per -- 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
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 77f93c3..471ed82 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -310,6 +310,14 @@ 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]; + + /* detect whether the eMMC card support BKOPS */ + if (ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1) { + card->ext_csd.bkops = 1; + card->ext_csd.bkops_en = + ext_csd[EXT_CSD_BKOPS_EN]; + } + } if (ext_csd[EXT_CSD_ERASED_MEM_CONT]) @@ -484,6 +492,24 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, } /* + * enable BKOPS if eMMC card supports. + */ + if (card->ext_csd.bkops) { + if (!card->ext_csd.bkops_en) { + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, + EXT_CSD_BKOPS_EN, 1); + if (err && err != -EBADMSG) + goto free_card; + + if (err) { + card->ext_csd.bkops_en = 0; + err = 0; + } else + card->ext_csd.bkops_en = 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..9b755cb 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -54,6 +54,8 @@ 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 bkops:1; /* background support bit */ + unsigned int bkops_en:1; /* background enable bit */ }; struct sd_scr { diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h index 956fbd8..14f7813 100644 --- a/include/linux/mmc/mmc.h +++ b/include/linux/mmc/mmc.h @@ -251,6 +251,8 @@ struct _mmc_csd { * EXT_CSD fields */ +#define EXT_CSD_BKOPS_EN 163 /* R/W */ +#define EXT_CSD_BKOPS_START 164 /* 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 */ @@ -266,6 +268,7 @@ struct _mmc_csd { #define EXT_CSD_SEC_ERASE_MULT 230 /* RO */ #define EXT_CSD_SEC_FEATURE_SUPPORT 231 /* RO */ #define EXT_CSD_TRIM_MULT 232 /* RO */ +#define EXT_CSD_BKOPS_SUPPORT 502 /* RO */ /* * EXT_CSD field definitions