[DEBUG] rk3399-nanopi-neo4: SPL SD init may report -5 due to SD power-on timing

[Sune Brian]

> My M4B could boot using sd-card without any issue last time I tested.
>
> I do not understand the purpose of your original mail when you do not
> seem to be willing to test suggestions from board maintainers. I will
> most likely just ignore any more replies from you, sorry.

First allow me to clarify the purpose of this email.

1) There are no reports from any user in the first place, could
this only be one specific board issue.

2) I never said I won't try your suggestion, however, the delay method
itself is a very bad method unless there is no choice to do so.

3) If there are board users mentioned this is not the case then why
cont'd debug on such? As the LDO delay might not be the root cause.

4) It is not guarantee my observation is what actually happened on
the boot error or stall.

Based on the 4 points I had given.

Could this be a board QC issue? aka one specific report only.
Could the inherent issue not be caused by the LDO startup time?
So more samples and feedback could help a lot to resolve the
stability.

Not simply using a delay test to conclude all things, this is what
I thought.

I appreciate the feedback on your board is not having issue.
Then with almost the same hardware design why does
NANOPI NEO4 have this issue?

If you feel I wasted your time on feedback and suggestions
I deeply sorry on that, but I never mentioned I am not trying to
take suggestions on your side. I am just playing very safe on this
issue as this could not be a simple timing issue.

Brian