Hi Jonas,
This patch resolves the previous boot issue mentioned earlier on the mailing
list:
[DEBUG] rk3399-nanopi-neo4: SPL SD init may report -5 due to SD power-on timing
Quoting the earlier observation:
"
While testing mainline U-Boot (v2026.01-rc1-00070-ge34d01d23e45) on the
FriendlyARM NanoPi NEO4 (RK3399), I observed that SPL sometimes fails to
initialize the SD card with the following message:
spl: mmc init failed with error: -5
SPL: failed to boot from all boot devices
"
So the NanoPi NEO4 boot stall appears to have been caused by the previous
regulator patch.
However, it is puzzling why the issue only affected SD boot and not MMC.
This suggests that the delay method proposed earlier regarding power-on timing
is not the actual root cause of the RK3399 NanoPi NEO4 SD boot stall.
Tested with this patch applied, and SD boot now works normally.
Regards,
Brian
