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

[Jonas Karlman]

Hi Brian,

On 10/31/2025 10:02 PM, Sune Brian wrote:
>> Your original mail mentions "sometimes fails" and that you tested U-Boot
>> v2026.01-rc1+, the most recent change for the nanpi4 family was related
>> to sd-card regulator handling to improve reboot when card was using uhs
>> speed in os and boot fails in spl due to this.
> 
> I cant 100% conclude all boards and situations so I used "sometimes".
> 
>> Please try my suggestion above, the datasheet for the LDO mention 50us
>> start-time and card may need one ms to fully init. Defining this timing
>> requirement in the device tree that U-Boot SPL uses should match the
>> workaround/fix you mention in your original mail.
> 
> w/o modification do your board experience any sd card error or stall during
> boot phase?

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.

Regards,
Jonas

> 
> brian