net: phy: Allow EEE for all RGMII variants

commit 7e140696 upstream.

RGMII interfaces come in multiple flavors: RGMII with transmit or
receive internal delay, no delays at all, or delays in both direction.

This change extends the initial check for PHY_INTERFACE_MODE_RGMII to
cover all of these variants since EEE should be allowed for any of these
modes, since it is a property of the RGMII, hence Gigabit PHY capability
more than the RGMII electrical interface and its delays.

Fixes: a59a4d19 ("phy: add the EEE support and the way to access to the MMD registers")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/phy/phy.c

@@ -1002,12 +1002,14 @@ int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable)
 {
 	/* According to 802.3az,the EEE is supported only in full duplex-mode.
 	 * Also EEE feature is active when core is operating with MII, GMII
-	 * or RGMII.
+	 * or RGMII (all kinds). Internal PHYs are also allowed to proceed and
+	 * should return an error if they do not support EEE.
 	 */
 	if ((phydev->duplex == DUPLEX_FULL) &&
 	    ((phydev->interface == PHY_INTERFACE_MODE_MII) ||
 	    (phydev->interface == PHY_INTERFACE_MODE_GMII) ||
-	    (phydev->interface == PHY_INTERFACE_MODE_RGMII))) {
+	    (phydev->interface >= PHY_INTERFACE_MODE_RGMII &&
+	     phydev->interface <= PHY_INTERFACE_MODE_RGMII_TXID))) {
 		int eee_lp, eee_cap, eee_adv;
 		u32 lp, cap, adv;
 		int status;