RE: [PATCH v5 2/2] mmc: core: Support packed command for eMMC4.5 device

[merez@codeaurora.org]

> Maya Erez <merez@codeaurora.org> wrote:
>> > Hi. Merez.
>> >
>> > Thanks a lot about your performance measurement.
>> >
>> > I think that your measurement is enough and correct and the firmware
>> > of mmc vender should be optimized or change properly rather than
>> > modifying the current patch.
>> >
>> > And currently we can use only write packed cmd by my suggestion.
>> >
>> > I would like to add my reviewd-by tag in updated patches also.
>> >
>> > Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
>> >
>> > Thanks.
>>
>> I tend to disagree. Adding a massive amount of code that would be
>> disabled
>> can be risky. In case this code will not be in use it will not be
>> properly
>> tested and its reliability will be uncertain.
>>
> If you found something to be correct, please let me know that.
> It would be rightly appreciated.
>
> Best regards,
> Seungwon Jeon.
Hi Jeon,

The write packing code looks good to me.
However, the separation of read and write packing to different patches is
very important to us.
As I specified before, we decided to enable only the write packing. We
plan to thoroughly test the write packing (edge cases and error handling)
and will not test the read packing. Therefore we would like to have the
ability to get only the write packing code.
In my previous comment I talked about the risk of mainlining  a “dead”
code. Every feature that is integrated is considered to be fully tested
and in the future it might be enabled, assuming that is was already
tested.
Can you please specify how you tested the read and write packing? Did you
perform edge cases and error handling tests? Do you have test code that
can be shared?

Thanks,
Maya Erez
Consultant for Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum