The root cause is found to be Ubuntu problem. Ubuntu built-in driver for Realtek has used the incorrect 8169.ko. 8169.ko will cause two registers inside LAN GPHY to have incorrect values, thus, causing the LAN GPHY stops working after system shuts down from Ubuntu. To solve this, you must clean out the built-in 8169.ko from Ubuntu. Install the correct driver from Realtek website 8168.ko.
All the motherboard vendors who ever using the Realtek LAN will have the same problem. Since it is the lousy Ubuntu built-in driver.
All the motherboard vendors who ever using the Realtek LAN will have the same problem. Since it is the lousy Ubuntu built-in driver.