[PATCH net 1/1] net: stmmac: update MAC capabilities when tx queues are updated

[Gan, Yi Fang]

From: Michael Sit Wei Hong <michael.wei.hong.sit@xxxxxxxxx>

Upon boot up, the driver will configure the MAC capabilities based on
the maximum number of tx and rx queues. When the user changes the
tx queues to single queue, the MAC should be capable of supporting Half
Duplex, but the driver does not update the MAC capabilities when it is
configured so.

Using the stmmac_reinit_queues() to check the number of tx queues
and set the MAC capabilities accordingly.

Fixes: 0366f7e06a6b ("net: stmmac: add ethtool support for get/set channels")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.17+
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@xxxxxxxxx>
Signed-off-by: Gan, Yi Fang <yi.fang.gan@xxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ed1a5a31a491..7ddc33fa0cb5 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7172,6 +7172,14 @@ int stmmac_reinit_queues(struct net_device *dev, u32 rx_cnt, u32 tx_cnt)
 			priv->rss.table[i] = ethtool_rxfh_indir_default(i,
 									rx_cnt);
 
+	/* Half-Duplex can only work with single tx queue */
+	if (priv->plat->tx_queues_to_use > 1)
+		priv->phylink_config.mac_capabilities &=
+			~(MAC_10HD | MAC_100HD | MAC_1000HD);
+	else
+		priv->phylink_config.mac_capabilities |=
+			(MAC_10HD | MAC_100HD | MAC_1000HD);
+
 	stmmac_napi_add(dev);
 
 	if (netif_running(dev))
-- 
2.34.1