quoted

+/* AGE_TIME_COEF is not documented. This is "works for me" value */
+#define AR9331_SW_AT_AGE_TIME_COEF		6900

Not documented, not used either, it seems.
"Works for you" based on what?

It is used in a later patch. Ideally it would of been introduced in
that patch to make this more obvious.

quoted

 #define AR9331_SW_REG_MDIO_CTRL			0x98
 #define AR9331_SW_MDIO_CTRL_BUSY		BIT(31)
 #define AR9331_SW_MDIO_CTRL_MASTER_EN		BIT(30)

@@ -101,6 +111,46 @@
 	 AR9331_SW_PORT_STATUS_RX_FLOW_EN | AR9331_SW_PORT_STATUS_TX_FLOW_EN | \
 	 AR9331_SW_PORT_STATUS_SPEED_M)

Is this patch material for "net"? If standalone ports is all that ar9331
supports, then it would better not do packet forwarding in lack of a
bridge device.

It does seem like this patch should be considered for stable, if by
default all ports can talk with all ports when not part of a bridge.

	Andrew