Hi, Alex. On 11/27/2014 01:38 AM, Alex Lemberg wrote: > Hi Jaehoon, > > Thank you for reviewing the patch. > >> -----Original Message----- >> From: Jaehoon Chung [mailto:jh80.chung@xxxxxxxxxxx] >> Sent: Wednesday, November 26, 2014 6:33 AM >> To: Alex Lemberg; ulf.hansson@xxxxxxxxxx >> Cc: linux-mmc@xxxxxxxxxxxxxxx; chris@xxxxxxxxxx; Avi Shchislowski >> Subject: Re: [PATCH v2] mmc: Add Production State Awareness Support >> >> Hi, >> >> On 11/26/2014 12:01 AM, Alex Lemberg wrote: >>> In this patch driver should recognize if eMMC device (Rev >=5.0) was >>> left in PRE_SOLDERING_POST_WRITES (0x02) state, and switch it to >>> NORMAL (0x00). >>> PRE_SOLDERING_POST_WRITES (0x02) state - represents a state where the >>> device is in production process and the host (usually programmer) >>> completed loading the content to the device. >>> The host (usually programmer) sets the device to this state after >>> loading the content and just before soldering. >>> After soldering the device to the real host (not programmer), the >>> device should be switched to NORMAL (0x00) mode. >>> The NORMAL (0x00) mode of PSA register represents a state in which the >>> device is running in the field and uses regular operations. >>> Leaving device in PRE_SOLDERING_POST_WRITES (0x02) might cause >>> unexpected behaviour of eMMC device. >>> >>> More details about PSA feature can be found in eMMC5.0 JEDEC spec >> (JESD84-B50.pdf): >>> http://www.jedec.org/standards-documents/technology-focus-areas/flash- >>> memory-ssds-ufs-emmc/e-mmc >>> >>> Signed-off-by: Alex Lemberg <alex.lemberg@xxxxxxxxxxx> >>> --- >>> Changes in v2: >>> - Remove typo in patch code >>> --- >>> drivers/mmc/core/mmc.c | 28 ++++++++++++++++++++++++++++ >>> include/linux/mmc/card.h | 2 ++ >>> include/linux/mmc/mmc.h | 8 ++++++++ >>> 3 files changed, 38 insertions(+) >>> >>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index >>> 02ad792..3923c90 100644 >>> --- a/drivers/mmc/core/mmc.c >>> +++ b/drivers/mmc/core/mmc.c >>> @@ -571,6 +571,16 @@ static int mmc_decode_ext_csd(struct mmc_card >> *card, u8 *ext_csd) >>> card->ext_csd.ffu_capable = >>> (ext_csd[EXT_CSD_SUPPORTED_MODE] & 0x1) && >>> !(ext_csd[EXT_CSD_FW_CONFIG] & 0x1); >>> + card->ext_csd.psa = >>> + ext_csd[EXT_CSD_PSA]; >>> + if (ext_csd[EXT_CSD_PSA_TIMEOUT] > 0) { >>> + card->ext_csd.psa_timeout = >>> + 100 * >>> + (1 << ext_csd[EXT_CSD_PSA_TIMEOUT]); >>> + } else { >>> + pr_warn("%s: EXT_CSD PSA Timeout is zero\n", >>> + mmc_hostname(card->host)); >> >> I remembered Ulf's previous comment. Did you check it? > Are you referring to psa_timeout? > In case it is zero, we are printing warning, and let host controller > to handle this. > Every switch command timeout setting in mmc driver done in this way. pr_warn() doesn't need. >> >>> + } >>> } >>> out: >>> return err; >>> @@ -1331,6 +1341,24 @@ static int mmc_init_card(struct mmc_host *host, >> u32 ocr, >>> mmc_set_dsr(host); >>> >>> /* >>> + * eMMC v5.0 or later >>> + * and Production State Awareness state is >>> + * EXT_CSD_PSA_POST_SOLDERING_WRITES (0x02) >>> + * The host should set the device to NORMAL mode >>> + */ >>> + if ((card->ext_csd.rev >= 7) && >>> + (card->ext_csd.psa == >> EXT_CSD_PSA_POST_SOLDERING_WRITES)) { >> >> Is it right? how did you get "revision"? > > In linux-next, the EXT_CSD revision set was moved > to mmc_decode_ext_csd() function. > Anyway, thanks for pointing me on this, I will move this check to > the right place. > >> >>> + unsigned int timeout; >>> + >>> + timeout = DIV_ROUND_UP(card->ext_csd.psa_timeout, 1000); >>> + card->ext_csd.psa = EXT_CSD_PSA_NORMAL; >> >> Why did card->ext_csd.psa assign to EXT_CSD_PSA_NORMAL as hard-coding? >> > I think this is a right way to set ext_csd structure in order to prevent additional read > from device ext_csd register, which was already read during the init. I think you assume that card is already initialized. In my understanding for your code. a) init time card->ext_csd.psa assigned to EXT_CSD_PSA_NORMAL. (hard coding) And switch to EXT_CSD_PSA_NORMAL. b) If oldcard doesn't present, try to read ext_csd register. Then EXT_CSD_PSA was always set to EXT_CSD_PSA_NORMAL. isn't? And card->ext_csd.psa is re-assigned to EXT_CSD_PSA register value. (It's also EXT_CSD_PSA_NORMAL, because it's switched to EXT_CSD_PSA_NORMA at 'a)' ) If i missed something, let me know. > > >>> + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, >>> + EXT_CSD_PSA, card->ext_csd.psa, timeout); If you need to change, err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PSA, EXT_CSD_PSA_NORMAL, timeout); Anyway, this sequence is something strange. Best Regards, Jaehoon Chung >>> + if (err && err != -EBADMSG) >>> + goto free_card; >>> + } >>> + >>> + /* >>> * Select card, as all following commands rely on that. >>> */ >>> if (!mmc_host_is_spi(host)) { >>> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index >>> 4d69c00..09ac3b0 100644 >>> --- a/include/linux/mmc/card.h >>> +++ b/include/linux/mmc/card.h >>> @@ -60,9 +60,11 @@ struct mmc_ext_csd { >>> u8 packed_event_en; >>> unsigned int part_time; /* Units: ms */ >>> unsigned int sa_timeout; /* Units: 100ns */ >>> + unsigned int psa_timeout; /* Units: 100us */ >>> unsigned int generic_cmd6_time; /* Units: 10ms */ >>> unsigned int power_off_longtime; /* Units: ms */ >>> u8 power_off_notification; /* state */ >>> + u8 psa; /* production state awareness */ >>> unsigned int hs_max_dtr; >>> unsigned int hs200_max_dtr; >>> #define MMC_HIGH_26_MAX_DTR 26000000 >>> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h index >>> 49ad7a9..458814d 100644 >>> --- a/include/linux/mmc/mmc.h >>> +++ b/include/linux/mmc/mmc.h >>> @@ -285,6 +285,7 @@ struct _mmc_csd { >>> #define EXT_CSD_EXP_EVENTS_STATUS 54 /* RO, 2 bytes */ >>> #define EXT_CSD_EXP_EVENTS_CTRL 56 /* R/W, 2 bytes */ >>> #define EXT_CSD_DATA_SECTOR_SIZE 61 /* R */ >>> +#define EXT_CSD_PSA 133 /* R/W/E */ >>> #define EXT_CSD_GP_SIZE_MULT 143 /* R/W */ >>> #define EXT_CSD_PARTITION_SETTING_COMPLETED 155 /* R/W */ >>> #define EXT_CSD_PARTITION_ATTRIBUTE 156 /* R/W */ >>> @@ -315,6 +316,7 @@ struct _mmc_csd { >>> #define EXT_CSD_PWR_CL_26_360 203 /* RO */ >>> #define EXT_CSD_SEC_CNT 212 /* RO, 4 bytes */ >>> #define EXT_CSD_S_A_TIMEOUT 217 /* RO */ >>> +#define EXT_CSD_PSA_TIMEOUT 218 /* RO */ >>> #define EXT_CSD_REL_WR_SEC_C 222 /* RO */ >>> #define EXT_CSD_HC_WP_GRP_SIZE 221 /* RO */ >>> #define EXT_CSD_ERASE_TIMEOUT_MULT 223 /* RO */ >>> @@ -433,6 +435,12 @@ struct _mmc_csd { >>> #define EXT_CSD_BKOPS_LEVEL_2 0x2 >>> >>> /* >>> + * PRODUCTION STATE AWARENESS fields >>> + */ >>> +#define EXT_CSD_PSA_NORMAL 0x00 >>> +#define EXT_CSD_PSA_POST_SOLDERING_WRITES 0x02 >>> + >>> +/* >>> * MMC_SWITCH access modes >>> */ >>> >>> > > -- 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
