amd-xgbe: Always attempt link training in KR mode

Link training is always attempted when in KR mode, but the code is
structured to check if link training has been enabled before attempting
to perform it.  Since that check will always be true, simplify the code
to always enable and start link training during KR auto-negotiation.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-mdio.c

@@ -216,31 +216,8 @@ static void xgbe_an_clear_interrupts_all(struct xgbe_prv_data *pdata)
 	xgbe_an37_clear_interrupts(pdata);
 }
 
-static void xgbe_an73_enable_kr_training(struct xgbe_prv_data *pdata)
-{
-	unsigned int reg;
-
-	reg = XMDIO_READ(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL);
-
-	reg |= XGBE_KR_TRAINING_ENABLE;
-	XMDIO_WRITE(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL, reg);
-}
-
-static void xgbe_an73_disable_kr_training(struct xgbe_prv_data *pdata)
-{
-	unsigned int reg;
-
-	reg = XMDIO_READ(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL);
-
-	reg &= ~XGBE_KR_TRAINING_ENABLE;
-	XMDIO_WRITE(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL, reg);
-}
-
 static void xgbe_kr_mode(struct xgbe_prv_data *pdata)
 {
-	/* Enable KR training */
-	xgbe_an73_enable_kr_training(pdata);
-
 	/* Set MAC to 10G speed */
 	pdata->hw_if.set_speed(pdata, SPEED_10000);
 
@@ -250,9 +227,6 @@ static void xgbe_kr_mode(struct xgbe_prv_data *pdata)
 
 static void xgbe_kx_2500_mode(struct xgbe_prv_data *pdata)
 {
-	/* Disable KR training */
-	xgbe_an73_disable_kr_training(pdata);
-
 	/* Set MAC to 2.5G speed */
 	pdata->hw_if.set_speed(pdata, SPEED_2500);
 
@@ -262,9 +236,6 @@ static void xgbe_kx_2500_mode(struct xgbe_prv_data *pdata)
 
 static void xgbe_kx_1000_mode(struct xgbe_prv_data *pdata)
 {
-	/* Disable KR training */
-	xgbe_an73_disable_kr_training(pdata);
-
 	/* Set MAC to 1G speed */
 	pdata->hw_if.set_speed(pdata, SPEED_1000);
 
@@ -278,9 +249,6 @@ static void xgbe_sfi_mode(struct xgbe_prv_data *pdata)
 	if (pdata->kr_redrv)
 		return xgbe_kr_mode(pdata);
 
-	/* Disable KR training */
-	xgbe_an73_disable_kr_training(pdata);
-
 	/* Set MAC to 10G speed */
 	pdata->hw_if.set_speed(pdata, SPEED_10000);
 
@@ -290,9 +258,6 @@ static void xgbe_sfi_mode(struct xgbe_prv_data *pdata)
 
 static void xgbe_x_mode(struct xgbe_prv_data *pdata)
 {
-	/* Disable KR training */
-	xgbe_an73_disable_kr_training(pdata);
-
 	/* Set MAC to 1G speed */
 	pdata->hw_if.set_speed(pdata, SPEED_1000);
 
@@ -302,9 +267,6 @@ static void xgbe_x_mode(struct xgbe_prv_data *pdata)
 
 static void xgbe_sgmii_1000_mode(struct xgbe_prv_data *pdata)
 {
-	/* Disable KR training */
-	xgbe_an73_disable_kr_training(pdata);
-
 	/* Set MAC to 1G speed */
 	pdata->hw_if.set_speed(pdata, SPEED_1000);
 
@@ -314,9 +276,6 @@ static void xgbe_sgmii_1000_mode(struct xgbe_prv_data *pdata)
 
 static void xgbe_sgmii_100_mode(struct xgbe_prv_data *pdata)
 {
-	/* Disable KR training */
-	xgbe_an73_disable_kr_training(pdata);
-
 	/* Set MAC to 1G speed */
 	pdata->hw_if.set_speed(pdata, SPEED_1000);
 
@@ -425,6 +384,12 @@ static void xgbe_an73_set(struct xgbe_prv_data *pdata, bool enable,
 {
 	unsigned int reg;
 
+	/* Disable KR training for now */
+	reg = XMDIO_READ(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL);
+	reg &= ~XGBE_KR_TRAINING_ENABLE;
+	XMDIO_WRITE(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL, reg);
+
+	/* Update AN settings */
 	reg = XMDIO_READ(pdata, MDIO_MMD_AN, MDIO_CTRL1);
 	reg &= ~MDIO_AN_CTRL1_ENABLE;
 
@@ -522,21 +487,19 @@ static enum xgbe_an xgbe_an73_tx_training(struct xgbe_prv_data *pdata,
 	XMDIO_WRITE(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_FECCTRL, reg);
 
 	/* Start KR training */
-	reg = XMDIO_READ(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL);
-	if (reg & XGBE_KR_TRAINING_ENABLE) {
 	if (pdata->phy_if.phy_impl.kr_training_pre)
 		pdata->phy_if.phy_impl.kr_training_pre(pdata);
 
+	reg = XMDIO_READ(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL);
+	reg |= XGBE_KR_TRAINING_ENABLE;
 	reg |= XGBE_KR_TRAINING_START;
-		XMDIO_WRITE(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL,
-			    reg);
+	XMDIO_WRITE(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_10GBR_PMD_CTRL, reg);
 
 	netif_dbg(pdata, link, pdata->netdev,
 		  "KR training initiated\n");
 
 	if (pdata->phy_if.phy_impl.kr_training_post)
 		pdata->phy_if.phy_impl.kr_training_post(pdata);
-	}
 
 	return XGBE_AN_PAGE_RECEIVED;
 }