I believe the POLL_SEL configuration actually affects an internal port
polling unit. From the datasheets I have it seems pretty configurable, you
can tell it which phy registers to poll and what values indicate link
up/down (the defaults are conveniently setup to match the Realtek PHYs).

You need to disable this. The linux PHY driver is driving the PHY, and
the hardware has no idea what Linux is doing. Say the driver has
changed the page to read a temperature sensor, when the switch does a
poll. Rather than reading the link status, it gets some random value
from the page containing the temperature sensor.

	Andrew