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

[Jaehoon Chung <jh80.chung@samsung.com>]

On 04/18/2012 09:20 AM, Namjae Jeon wrote:

> 2012/4/17 Venkatraman S <svenkatr@ti.com>:
>> 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 ?

Well, i know that timeout value is used the OUT_OF_INTERRUPT_TIME, when interrupted by HPI.
It's my misunderstanding?

Best Regards,
Jaehoon Chung

> 
> 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@sandisk.com>
>> Signed-off-by: Venkatraman S <svenkatr@ti.com>
>> CC: Namjae Jeon <linkinjeon@gmail.com>
>> CC: Jae hoon Chung <jh80.chung@gmail.com>
>> CC: Chris Ball <cjb@laptop.org>
>> ---
>> 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
>>
>