RE: [PATCH v2 1/2] [MMC-4.5] Disable emulation

["Subhash Jadavani" <subhashj@codeaurora.org>]

Looks good to me.
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>

Regards,
Subhash

> -----Original Message-----
> From: Saugata Das [mailto:saugata.das@stericsson.com]
> Sent: Thursday, May 17, 2012 4:32 PM
> To: linux-mmc@vger.kernel.org
> Cc: patches@linaro.org; saugata.das@linaro.org; subhashj@codeaurora.org;
> arnd.bergmann@linaro.org; venkat@linaro.org; lporzio@micron.com;
> linkinjeon@gmail.com
> Subject: [PATCH v2 1/2] [MMC-4.5] Disable emulation
> 
> From: Saugata Das <saugata.das@linaro.org>
> 
> This patch adds the support for large sector size of 4KB by disabling
> emulation.
> This patch passes eMMC DATA_SECTOR_SIZE as the logical block size during
> mmc_blk_alloc_req.
> 
> In order to use this patch for 4KB sector size, ensure that
> USE_NATIVE_SECTOR is enabled, partition table is 4KB sector size aligned
and
> file system block and sector size are 4KB multiples.
> 
> Signed-off-by: Saugata Das <saugata.das@linaro.org>
> 
> changes in v2:
> 	Updated description, added pr_err based on review feedback
> ---
>  drivers/mmc/card/block.c |   18 ++++++++++++++++--
>  drivers/mmc/core/mmc.c   |    2 ++
>  2 files changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index
> 91cda75..d628c5d 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1284,7 +1284,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue
> *mq, struct request *rqc)
>  	int ret = 1, disable_multi = 0, retry = 0, type;
>  	enum mmc_blk_status status;
>  	struct mmc_queue_req *mq_rq;
> -	struct request *req;
> +	struct request *req = rqc;
>  	struct mmc_async_req *areq;
> 
>  	if (!rqc && !mq->mqrq_prev->req)
> @@ -1292,6 +1292,16 @@ static int mmc_blk_issue_rw_rq(struct
> mmc_queue *mq, struct request *rqc)
> 
>  	do {
>  		if (rqc) {
> +			/*
> +			 * When 4KB native sector is enabled, only 8 blocks
> +			 * multiple read or write is allowed
> +			 */
> +			if ((brq->data.blocks & 0x07) &&
> +				(card->ext_csd.data_sector_size == 4096)) {
> +				pr_err("%s: Transfer size is not 4KB sector
> size aligned\n",
> +					req->rq_disk->disk_name);
> +				goto cmd_abort;
> +			}
>  			mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
>  			areq = &mq->mqrq_cur->mmc_active;
>  		} else
> @@ -1539,7 +1549,11 @@ static struct mmc_blk_data
> *mmc_blk_alloc_req(struct mmc_card *card,
>  	snprintf(md->disk->disk_name, sizeof(md->disk->disk_name),
>  		 "mmcblk%d%s", md->name_idx, subname ? subname : "");
> 
> -	blk_queue_logical_block_size(md->queue.queue, 512);
> +	if (mmc_card_mmc(card))
> +		blk_queue_logical_block_size(md->queue.queue,
> +			card->ext_csd.data_sector_size);
> +	else
> +		blk_queue_logical_block_size(md->queue.queue, 512);
>  	set_capacity(md->disk, size);
> 
>  	if (mmc_host_cmd23(card->host)) {
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index
> 7268c26..11444c6 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -516,6 +516,8 @@ static int mmc_read_ext_csd(struct mmc_card *card,
> u8 *ext_csd)
>  		} else {
>  			card->ext_csd.data_tag_unit_size = 0;
>  		}
> +	} else {
> +		card->ext_csd.data_sector_size = 512;
>  	}
> 
>  out:
> --
> 1.7.4.3