Re: [PATCH v2] mmc: core: Fix the HPI execution sequence

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2012/4/17 Venkatraman S <svenkatr@xxxxxx>:
> mmc_execute_hpi should send the HPI command only
> once, only if the card is in PRG state.
>
> According to eMMC spec, the command's completion time is
> not dependent on OUT_OF_INTERRUPT_TIME. Only the transition
> out of PRG STATE is guarded by OUT_OF_INTERRUPT_TIME - which is
> defined to begin at the end of sending the command itself.
Hi. Venkatraman.
I can not find this words. " the command's completion time is not
dependent on OUT_OF_INTERRUPT_TIME" .
Would you inform me which page and which part you checked in specification ?

Thanks.
>
> Specify the default timeout for the actual sending of HPI
> command, and then use OUT_OF_INTERRUPT_TIME to wait for
> the transition out of PRG state.
>
> Reported-by: Alex Lemberg <Alex.Lemberg@xxxxxxxxxxx>
> Signed-off-by: Venkatraman S <svenkatr@xxxxxx>
> CC: Namjae Jeon <linkinjeon@xxxxxxxxx>
> CC: Jae hoon Chung <jh80.chung@xxxxxxxxx>
> CC: Chris Ball <cjb@xxxxxxxxxx>
> ---
> Changes since v1:
>        Skip looping over send_status indefinitely
>        Correct the interpretation of OUT_OF_INTERRUPT_TIME
>
>  drivers/mmc/core/core.c    |   45 ++++++++++++++++++++++++--------------------
>  drivers/mmc/core/mmc_ops.c |    2 +-
>  2 files changed, 26 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index e541efb..027c579 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -403,6 +403,7 @@ int mmc_interrupt_hpi(struct mmc_card *card)
>  {
>        int err;
>        u32 status;
> +       unsigned long starttime;
>
>        BUG_ON(!card);
>
> @@ -421,27 +422,31 @@ int mmc_interrupt_hpi(struct mmc_card *card)
>        /*
>         * If the card status is in PRG-state, we can send the HPI command.
>         */
> -       if (R1_CURRENT_STATE(status) == R1_STATE_PRG) {
> -               do {
> -                       /*
> -                        * We don't know when the HPI command will finish
> -                        * processing, so we need to resend HPI until out
> -                        * of prg-state, and keep checking the card status
> -                        * with SEND_STATUS.  If a timeout error occurs when
> -                        * sending the HPI command, we are already out of
> -                        * prg-state.
> -                        */
> -                       err = mmc_send_hpi_cmd(card, &status);
> -                       if (err)
> -                               pr_debug("%s: abort HPI (%d error)\n",
> -                                        mmc_hostname(card->host), err);
> +       if (R1_CURRENT_STATE(status) != R1_STATE_PRG) {
> +               pr_debug("%s: Can't send HPI: Card state=%d\n",
> +                       mmc_hostname(card->host), R1_CURRENT_STATE(status));
> +               err = -EINVAL;
> +               goto out;
> +       }
> +
> +       starttime = jiffies;
> +       err = mmc_send_hpi_cmd(card, &status);
> +       if (err) {
> +               pr_debug("%s:HPI could not be sent.err=%d)\n",
> +                       mmc_hostname(card->host), err);
> +               goto out;
> +       }
> +
> +       do {
> +               err = mmc_send_status(card, &status);
> +
> +               if (!err && R1_CURRENT_STATE(status) == R1_STATE_TRAN)
> +                       goto out;
> +               if (jiffies_to_msecs(jiffies - starttime) >
> +                       card->ext_csd.out_of_int_time)
> +                       err = -ETIMEDOUT;
> +       } while (!err);
>
> -                       err = mmc_send_status(card, &status);
> -                       if (err)
> -                               break;
> -               } while (R1_CURRENT_STATE(status) == R1_STATE_PRG);
> -       } else
> -               pr_debug("%s: Left prg-state\n", mmc_hostname(card->host));
>
>  out:
>        mmc_release_host(card->host);
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index 69370f4..f2235d6 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -569,7 +569,7 @@ int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status)
>
>        cmd.opcode = opcode;
>        cmd.arg = card->rca << 16 | 1;
> -       cmd.cmd_timeout_ms = card->ext_csd.out_of_int_time;
> +       cmd.cmd_timeout_ms = 0;
>
>        err = mmc_wait_for_cmd(card->host, &cmd, 0);
>        if (err) {
> --
> 1.7.10.rc2
>
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