[PATCH v3 net-next 11/13] net: dsa: felix: support half-duplex link modes

[Vladimir Oltean <olteanv@gmail.com>]

From: Vladimir Oltean <vladimir.oltean@nxp.com>

Ping tested:

  [   11.808455] mscc_felix 0000:00:00.5 swp0: Link is Up - 1Gbps/Full - flow control rx/tx
  [   11.816497] IPv6: ADDRCONF(NETDEV_CHANGE): swp0: link becomes ready

  [root@LS1028ARDB ~] # ethtool -s swp0 advertise 0x4
  [   18.844591] mscc_felix 0000:00:00.5 swp0: Link is Down
  [   22.048337] mscc_felix 0000:00:00.5 swp0: Link is Up - 100Mbps/Half - flow control off

  [root@LS1028ARDB ~] # ip addr add 192.168.1.1/24 dev swp0

  [root@LS1028ARDB ~] # ping 192.168.1.2
  PING 192.168.1.2 (192.168.1.2): 56 data bytes
  (...)
  ^C--- 192.168.1.2 ping statistics ---
  3 packets transmitted, 3 packets received, 0% packet loss
  round-trip min/avg/max = 0.383/0.611/1.051 ms

  [root@LS1028ARDB ~] # ethtool -s swp0 advertise 0x10
  [  355.637747] mscc_felix 0000:00:00.5 swp0: Link is Down
  [  358.788034] mscc_felix 0000:00:00.5 swp0: Link is Up - 1Gbps/Half - flow control off

  [root@LS1028ARDB ~] # ping 192.168.1.2
  PING 192.168.1.2 (192.168.1.2): 56 data bytes
  (...)
  ^C
  --- 192.168.1.2 ping statistics ---
  16 packets transmitted, 16 packets received, 0% packet loss
  round-trip min/avg/max = 0.301/0.384/1.138 ms

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
Patch resent from:
https://patchwork.ozlabs.org/project/netdev/patch/20200528094410.2658306-1-olteanv@gmail.com/

Changes in v3:
None.

Changes in v2:
Added spaces before the ping output in the commit message.

 drivers/net/dsa/ocelot/felix.c         |  4 +++-
 drivers/net/dsa/ocelot/felix_vsc9959.c | 13 ++++++++-----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 0346697bed3f..88b64faa8b25 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -167,14 +167,16 @@ static void felix_phylink_validate(struct dsa_switch *ds, int port,
 		return;
 	}
 
-	/* No half-duplex. */
 	phylink_set_port_modes(mask);
 	phylink_set(mask, Autoneg);
 	phylink_set(mask, Pause);
 	phylink_set(mask, Asym_Pause);
 	phylink_set(mask, 10baseT_Full);
+	phylink_set(mask, 10baseT_Half);
 	phylink_set(mask, 100baseT_Full);
+	phylink_set(mask, 100baseT_Half);
 	phylink_set(mask, 1000baseT_Full);
+	phylink_set(mask, 1000baseT_Half);
 
 	if (state->interface == PHY_INTERFACE_MODE_INTERNAL ||
 	    state->interface == PHY_INTERFACE_MODE_2500BASEX ||
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index e722b58a714f..61c91248a802 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -875,12 +875,12 @@ static void vsc9959_pcs_init_sgmii(struct phy_device *pcs,
 
 		phy_write(pcs, MII_BMCR, BMCR_ANRESTART | BMCR_ANENABLE);
 	} else {
+		u16 duplex = 0;
 		int speed;
 
-		if (state->duplex == DUPLEX_HALF) {
-			phydev_err(pcs, "Half duplex not supported\n");
-			return;
-		}
+		if (state->duplex == DUPLEX_FULL)
+			duplex = BMCR_FULLDPLX;
+
 		switch (state->speed) {
 		case SPEED_1000:
 			speed = ENETC_PCS_SPEED_1000;
@@ -906,7 +906,7 @@ static void vsc9959_pcs_init_sgmii(struct phy_device *pcs,
 		/* Yes, not a mistake: speed is given by IF_MODE. */
 		phy_write(pcs, MII_BMCR, BMCR_RESET |
 					 BMCR_SPEED1000 |
-					 BMCR_FULLDPLX);
+					 duplex);
 	}
 }
 
@@ -983,8 +983,11 @@ static void vsc9959_pcs_init(struct ocelot *ocelot, int port,
 			       ARRAY_SIZE(phy_basic_ports_array),
 			       pcs->supported);
 	linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, pcs->supported);
+	linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, pcs->supported);
 	linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, pcs->supported);
+	linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT, pcs->supported);
 	linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, pcs->supported);
+	linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, pcs->supported);
 	if (pcs->interface == PHY_INTERFACE_MODE_2500BASEX ||
 	    pcs->interface == PHY_INTERFACE_MODE_USXGMII)
 		linkmode_set_bit(ETHTOOL_LINK_MODE_2500baseX_Full_BIT,
-- 
2.25.1