RE: [PATCH] mmc: block: Add single read for 4k sector cards

[Avri Altman <Avri.Altman@wdc.com>]

Hi,

> Cards with 4k native sector size may only be read 4k-aligned,
> accommodate for this in the single read recovery and use it.

Fixes: 2bf22b39823c (mmc: core: add workaround for controllers with broken multiblock reads)
> 
> Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
> ---
>  drivers/mmc/core/block.c | 26 ++++++++++++++------------
>  1 file changed, 14 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index f4a1281658db..6f0b24cb0747 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -176,7 +176,7 @@ static inline int mmc_blk_part_switch(struct
> mmc_card *card,
>                                       unsigned int part_type);
>  static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
>                                struct mmc_card *card,
> -                              int disable_multi,
> +                              int recovery_mode,
>                                struct mmc_queue *mq);
>  static void mmc_blk_hsq_req_done(struct mmc_request *mrq);
> 
> @@ -1302,7 +1302,7 @@ static void mmc_blk_eval_resp_error(struct
> mmc_blk_request *brq)
>  }
> 
>  static void mmc_blk_data_prep(struct mmc_queue *mq, struct
> mmc_queue_req *mqrq,
> -                             int disable_multi, bool *do_rel_wr_p,
> +                             int recovery_mode, bool *do_rel_wr_p,
>                               bool *do_data_tag_p)
>  {
>         struct mmc_blk_data *md = mq->blkdata;
> @@ -1372,8 +1372,11 @@ static void mmc_blk_data_prep(struct
> mmc_queue *mq, struct mmc_queue_req *mqrq,
>                  * at a time in order to accurately determine which
>                  * sectors can be read successfully.
>                  */
> -               if (disable_multi)
> +               if (recovery_mode) {
>                         brq->data.blocks = 1;
> +                       if (mmc_large_sector(card))
> +                               brq->data.blocks = 8;
Maybe a ternary operator here?
 
> +               }
> 
>                 /*
>                  * Some controllers have HW issues while operating
> @@ -1590,7 +1593,7 @@ static int mmc_blk_cqe_issue_rw_rq(struct
> mmc_queue *mq, struct request *req)
> 
>  static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
>                                struct mmc_card *card,
> -                              int disable_multi,
> +                              int recovery_mode,
>                                struct mmc_queue *mq)
>  {
>         u32 readcmd, writecmd;
> @@ -1599,7 +1602,7 @@ static void mmc_blk_rw_rq_prep(struct
> mmc_queue_req *mqrq,
>         struct mmc_blk_data *md = mq->blkdata;
>         bool do_rel_wr, do_data_tag;
> 
> -       mmc_blk_data_prep(mq, mqrq, disable_multi, &do_rel_wr,
> &do_data_tag);
> +       mmc_blk_data_prep(mq, mqrq, recovery_mode, &do_rel_wr,
> &do_data_tag);
> 
>         brq->mrq.cmd = &brq->cmd;
> 
> @@ -1690,7 +1693,7 @@ static int mmc_blk_fix_state(struct mmc_card
> *card, struct request *req)
> 
>  #define MMC_READ_SINGLE_RETRIES        2
> 
> -/* Single sector read during recovery */
> +/* Single (native) sector read during recovery */
>  static void mmc_blk_read_single(struct mmc_queue *mq, struct request
> *req)
>  {
>         struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
> @@ -1698,6 +1701,7 @@ static void mmc_blk_read_single(struct
> mmc_queue *mq, struct request *req)
>         struct mmc_card *card = mq->card;
>         struct mmc_host *host = card->host;
>         blk_status_t error = BLK_STS_OK;
> +       size_t bytes_per_read = mmc_large_sector(card) ? 4069 : 512;
Typo: 4069 -> 4096

Thanks,
Avri
> 
>         do {
>                 u32 status;
> @@ -1732,13 +1736,13 @@ static void mmc_blk_read_single(struct
> mmc_queue *mq, struct request *req)
>                 else
>                         error = BLK_STS_OK;
> 
> -       } while (blk_update_request(req, error, 512));
> +       } while (blk_update_request(req, error, bytes_per_read));
> 
>         return;
> 
>  error_exit:
>         mrq->data->bytes_xfered = 0;
> -       blk_update_request(req, BLK_STS_IOERR, 512);
> +       blk_update_request(req, BLK_STS_IOERR, bytes_per_read);
>         /* Let it try the remaining request again */
>         if (mqrq->retries > MMC_MAX_RETRIES - 1)
>                 mqrq->retries = MMC_MAX_RETRIES - 1;
> @@ -1879,10 +1883,8 @@ static void mmc_blk_mq_rw_recovery(struct
> mmc_queue *mq, struct request *req)
>                 return;
>         }
> 
> -       /* FIXME: Missing single sector read for large sector size */
> -       if (!mmc_large_sector(card) && rq_data_dir(req) == READ &&
> -           brq->data.blocks > 1) {
> -               /* Read one sector at a time */
> +       if (rq_data_dir(req) == READ && brq->data.blocks > 1) {
> +               /* Read one (native) sector at a time */
>                 mmc_blk_read_single(mq, req);
>                 return;
>         }
> --
> 2.36.1
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