Boot needs up to 7 minutes on Ubuntu 16.04

[JulianM]

Hi together!

I need help with my Pine64 2GB RAM Board.

The problem is a very long boot time, if ethernet is unplugged. The systems hangs on "[XXXXXXXX] Call trace:".
Nothing else behind this note.
The system boots completely after 4-7 minutes, but only if ethernet is unplugged.
If ethernet is plugged in, the system starts within 1 minute.

It doesn't matter which version of Pine64 I'm using, because I already tried 512 MB, 1 GB and 2 GB of RAM.

Some information about my setup:
- Ubuntu 16.04 with updated kernel and U-Boot via update scripts.
- installed WiFi-/Bluetooth module.
- Static IP address via WiFi in /etc/network/interfaces and router.
- No connection via ethernet, just via WiFi.
- Samsung Evo microsd card.
- Official Pine64 power supply from Pine64 shop.
- Deleted standard MAC address.

Please help me with my little problem.

Best regards
Julian