PHY: Etherent PHY port may stall when coming out of power down

A software-defined mode change from PowerDown (Reg0.0x800) to AutoNeg (Reg0.0x1200) may stall under rare circumstances the Ethernet PHY port.

Phenomenon:

• Ethernet PHY port 1 does not establish a link but the link partner established a link.

Note:

• Phenomenon only affects the AutoNeg mode, not when switching into forced modes.

Do not switch into AutoNeg mode directly and use the interim state 10HDX:

• PowerDown (Reg0.0x800) → 10HDX forced (Reg0.0x0000) for 1 ms → Restart AutoNeg (Reg0.0x1200)