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

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

On 04/18/2012 05:42 PM, S, Venkatraman wrote:

> On Wed, Apr 18, 2012 at 1:53 PM, Namjae Jeon <linkinjeon@gmail.com> wrote:
>> 2012/4/18 S, Venkatraman <svenkatr@ti.com>:
>>> On Wed, Apr 18, 2012 at 10:15 AM, Namjae Jeon <linkinjeon@gmail.com> wrote:
>>>> 2012/4/18 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?
>>>> I agree, I also understand with you. But we should hear Venkatraman's
>>>> opinion from next reply.
>>>> see the spec.
>>>
>>> That particular line was explicit, *emphasis* mine..
>>> In Section 6.8.2 "OUT_OF_INTERRUPT_TIME defines the maximum time
>>> between the *end* bit of CMD12/13, arg[0]=1 to the DAT0 release of the
>>> device."
>>>
>>> Which essentially means the timer should start after the HPI command
>>> has been exchanged, and should normally end when the DAT0 line is
>>> released (in other words, move out of PRG state).
>>> You can see the same definition in Section 7.4.33
>>>
>>> The definition in 6.6.23, is partly confusing, for one it uses
>>> OUT_OF_INTERRUPT_BUSY_TIME and not OUT_OF_INTERRUPT_TIME, and other,
>>> it refers to the command being *interrupted by* HPI, not the HPI
>>> command itself.
>>>
>>> Let me know if this explains it a bit better.
>>>
>>> Best regards,
>>> Venkat.
>> Hi. Venkat.
>> You're right. OUT_OF_INTERRUPT_TIME is range between Busy line(Data0)
>> released by device and end bit of CMD 12,13.
>> and I would like you change some code in this patch.
>> I think that break is better than goto. because it is not duplicated loop.
>> +               if (!err && R1_CURRENT_STATE(status) == R1_STATE_TRAN)
>> +                       goto out;
>>
>> you don't need to initialize cmd_timeout_ms value. because you can see
>> struct mmc_command cmd = {0}; code.
>> +       cmd.cmd_timeout_ms = 0;
>>
>> Thanks.
>>
> 
> Great - thanks for your review and feedback. I'll post a new patch
> after making the changes you

Thanks for your explanation. it makes sense.
If you resend the patch, i will test with your patch.

Best Regards,
Jaehoon Chung

> requested.
> Regards,
> Venkat.
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