[PATCH] mmc: core: eMMC4.5 Add the timeout for switch

[Kukjin Kim]

Girish K S wrote:
> 
> This patch adds the code to handle the default timeout
> for switch command.
> For eMMC 4.5 devices if timeout is not specified for the switch
> command while accessing a specific field,then the default timeout
> shall be used to timeout. Specification says there is no timeout
> defined while accessing BKOPS_START, SANITIZE_START, FLUSH_CACHE
> field(so these fields are excluded).
> 
> Signed-off-by: Girish K S <girish.shivananjappa at linaro.org>
> ---
>  drivers/mmc/core/mmc.c     |    5 +++++
>  drivers/mmc/core/mmc_ops.c |    8 ++++++++
>  include/linux/mmc/card.h   |    1 +
>  include/linux/mmc/mmc.h    |    4 ++++
>  4 files changed, 18 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 5700b1c..5b9fb6a 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -405,6 +405,11 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8
> *ext_csd)
>  	if (card->ext_csd.rev >= 5)
>  		card->ext_csd.rel_param =
> ext_csd[EXT_CSD_WR_REL_PARAM];
> 
> +	if (card->ext_csd.rev > 5) {
> +		/* (eMMC 4.5)timeout is expressed in units of 10 ms*/
> +		card->ext_csd.cmd6_timeout =
> ext_csd[EXT_CSD_CMD6_TIME]*10;
> +	}
> +
>  	if (ext_csd[EXT_CSD_ERASED_MEM_CONT])
>  		card->erased_byte = 0xFF;
>  	else
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index 770c3d0..c4d82f4 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -394,6 +394,14 @@ int mmc_switch(struct mmc_card *card, u8 set, u8
index,
> u8 value,
>  	cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
>  	cmd.cmd_timeout_ms = timeout_ms;
> 
> +	/* timeout is not defined for below command indexes (eMMC 4.5) */
> +	if ((timeout_ms == 0)					&&
> +		(card->ext_csd->rev > 5)			&&
> +		(index != EXT_CSD_BKOPS_START)		&&
> +		(index != EXT_CSD_SANITIZE_START)	&&
> +		(index != EXT_CSD_FLUSH_CACHE))
> +			cmd.cmd_timeout_ms = card->ext_csd->cmd6_timeout;
> +
>  	err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
>  	if (err)
>  		return err;
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index b460fc2..ef88412 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -50,6 +50,7 @@ struct mmc_ext_csd {
>  	u8			rel_sectors;
>  	u8			rel_param;
>  	u8			part_config;
> +	u8			cmd6_timeout;	/* timeout in ms */
>  	unsigned int		part_time;		/* Units: ms */
>  	unsigned int		sa_timeout;		/* Units: 100ns */
>  	unsigned int		hs_max_dtr;
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index 5a794cb..a23f836 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -270,8 +270,11 @@ struct _mmc_csd {
>   * EXT_CSD fields
>   */
> 
> +#define EXT_CSD_FLUSH_CACHE		32	/* R/W */
>  #define EXT_CSD_PARTITION_ATTRIBUTE	156	/* R/W */
>  #define EXT_CSD_PARTITION_SUPPORT	160	/* RO */
> +#define EXT_CSD_BKOPS_START		164	/* R/W */
> +#define EXT_CSD_SANITIZE_START		165	/* R/W */
>  #define EXT_CSD_WR_REL_PARAM		166	/* RO */
>  #define EXT_CSD_ERASE_GROUP_DEF		175	/* R/W */
>  #define EXT_CSD_PART_CONFIG		179	/* R/W */
> @@ -293,6 +296,7 @@ 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_CMD6_TIME		248	/* RO */
> 
>  /*
>   * EXT_CSD field definitions
> --
> 1.7.1

Hi Girish,

(Cc'ed Seungwon Jeon)

As I know, Seungwon Jeon has been submitted same/similar patch before this.
http://www.spinics.net/lists/linux-mmc/msg09770.html

Chris,
I cannot find your review on that...

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.