On 18 August 2017 at 03:16, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote:
> We to some extent should tolerate R1_OUT_OF_RANGE for open-ending
> mode as it is expected behaviour and most of the backup partition
> tables should be located near some of the last blocks which will
> always make open-ending read exceed the capacity of cards.
>
> Fixes: 9820a5b11101 ("mmc: core: for data errors, take response of stop cmd into account")
> Fixes: a04e6bae9e6f ("mmc: core: check also R1 response for stop commands")
> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> Tested-by: Shawn Guo <shawnguo@xxxxxxxxxx>
Thanks, applied for fixes!
Kind regards
Uffe
> ---
>
> Changes in v4:
> - improve for more readable and remove Yoshihiro's tag, add Wolfram's
> tag
>
> Changes in v3:
> - add explanation for why don't check predefined method
> - check brq->mrq.sbc for easier to read suggested by Wolfram
>
> Changes in v2:
> - fix a typo and introduce STOP_ERROR
> - reword the comment and always include a description from the spec if possible
>
> drivers/mmc/core/block.c | 49 ++++++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 43 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index 91e1e93..b8fa62c 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -1369,12 +1369,46 @@ static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq,
> R1_CC_ERROR | /* Card controller error */ \
> R1_ERROR) /* General/unknown error */
>
> -static bool mmc_blk_has_cmd_err(struct mmc_command *cmd)
> +static void mmc_blk_eval_resp_error(struct mmc_blk_request *brq)
> {
> - if (!cmd->error && cmd->resp[0] & CMD_ERRORS)
> - cmd->error = -EIO;
> + u32 val;
>
> - return cmd->error;
> + /*
> + * Per the SD specification(physical layer version 4.10)[1],
> + * section 4.3.3, it explicitly states that "When the last
> + * block of user area is read using CMD18, the host should
> + * ignore OUT_OF_RANGE error that may occur even the sequence
> + * is correct". And JESD84-B51 for eMMC also has a similar
> + * statement on section 6.8.3.
> + *
> + * Multiple block read/write could be done by either predefined
> + * method, namely CMD23, or open-ending mode. For open-ending mode,
> + * we should ignore the OUT_OF_RANGE error as it's normal behaviour.
> + *
> + * However the spec[1] doesn't tell us whether we should also
> + * ignore that for predefined method. But per the spec[1], section
> + * 4.15 Set Block Count Command, it says"If illegal block count
> + * is set, out of range error will be indicated during read/write
> + * operation (For example, data transfer is stopped at user area
> + * boundary)." In another word, we could expect a out of range error
> + * in the response for the following CMD18/25. And if argument of
> + * CMD23 + the argument of CMD18/25 exceed the max number of blocks,
> + * we could also expect to get a -ETIMEDOUT or any error number from
> + * the host drivers due to missing data response(for write)/data(for
> + * read), as the cards will stop the data transfer by itself per the
> + * spec. So we only need to check R1_OUT_OF_RANGE for open-ending mode.
> + */
> +
> + if (!brq->stop.error) {
> + bool oor_with_open_end;
> + /* If there is no error yet, check R1 response */
> +
> + val = brq->stop.resp[0] & CMD_ERRORS;
> + oor_with_open_end = val & R1_OUT_OF_RANGE && !brq->mrq.sbc;
> +
> + if (val && !oor_with_open_end)
> + brq->stop.error = -EIO;
> + }
> }
>
> static enum mmc_blk_status mmc_blk_err_check(struct mmc_card *card,
> @@ -1398,8 +1432,11 @@ static enum mmc_blk_status mmc_blk_err_check(struct mmc_card *card,
> * stop.error indicates a problem with the stop command. Data
> * may have been transferred, or may still be transferring.
> */
> - if (brq->sbc.error || brq->cmd.error || mmc_blk_has_cmd_err(&brq->stop) ||
> - brq->data.error) {
> +
> + mmc_blk_eval_resp_error(brq);
> +
> + if (brq->sbc.error || brq->cmd.error ||
> + brq->stop.error || brq->data.error) {
> switch (mmc_blk_cmd_recovery(card, req, brq, &ecc_err, &gen_err)) {
> case ERR_RETRY:
> return MMC_BLK_RETRY;
> --
> 1.9.1
>
>
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