net: ethernet: mtk-star-emac: enable half duplex hardware support

Current driver doesn't support half duplex correctly.
This patch enable half duplex capability in hardware.
Signed-off-by: Biao Huang <biao.huang@mediatek.com>
Signed-off-by: Yinghua Pan <ot_yinghua.pan@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mediatek/mtk_star_emac.c

@@ -883,32 +883,26 @@ static void mtk_star_phy_config(struct mtk_star_priv *priv)
 	val <<= MTK_STAR_OFF_PHY_CTRL1_FORCE_SPD;
 
 	val |= MTK_STAR_BIT_PHY_CTRL1_AN_EN;
+	if (priv->pause) {
 		val |= MTK_STAR_BIT_PHY_CTRL1_FORCE_FC_RX;
 		val |= MTK_STAR_BIT_PHY_CTRL1_FORCE_FC_TX;
-	/* Only full-duplex supported for now. */
 		val |= MTK_STAR_BIT_PHY_CTRL1_FORCE_DPX;
-
+	} else {
+		val &= ~MTK_STAR_BIT_PHY_CTRL1_FORCE_FC_RX;
+		val &= ~MTK_STAR_BIT_PHY_CTRL1_FORCE_FC_TX;
+		val &= ~MTK_STAR_BIT_PHY_CTRL1_FORCE_DPX;
+	}
 	regmap_write(priv->regs, MTK_STAR_REG_PHY_CTRL1, val);
 
-	if (priv->pause) {
 	val = MTK_STAR_VAL_FC_CFG_SEND_PAUSE_TH_2K;
 	val <<= MTK_STAR_OFF_FC_CFG_SEND_PAUSE_TH;
 	val |= MTK_STAR_BIT_FC_CFG_UC_PAUSE_DIR;
-	} else {
-		val = 0;
-	}
-
 	regmap_update_bits(priv->regs, MTK_STAR_REG_FC_CFG,
 			   MTK_STAR_MSK_FC_CFG_SEND_PAUSE_TH |
 			   MTK_STAR_BIT_FC_CFG_UC_PAUSE_DIR, val);
 
-	if (priv->pause) {
 	val = MTK_STAR_VAL_EXT_CFG_SND_PAUSE_RLS_1K;
 	val <<= MTK_STAR_OFF_EXT_CFG_SND_PAUSE_RLS;
-	} else {
-		val = 0;
-	}
-
 	regmap_update_bits(priv->regs, MTK_STAR_REG_EXT_CFG,
 			   MTK_STAR_MSK_EXT_CFG_SND_PAUSE_RLS, val);
 }