[PATCH 1/2] net: amd-xgbe: Toggle PLL settings during rate change

@@ -1331,6 +1331,10 @@
 #define MDIO_VEND2_PMA_CDR_CONTROL	0x8056
 #endif
 
+#ifndef MDIO_VEND2_PMA_MISC_CTRL0
+#define MDIO_VEND2_PMA_MISC_CTRL0	0x8090
+#endif
+
 #ifndef MDIO_CTRL1_SPEED1G
 #define MDIO_CTRL1_SPEED1G		(MDIO_CTRL1_SPEED10G & ~BMCR_SPEED100)
 #endif

@@ -1389,6 +1393,10 @@
 #define XGBE_PMA_RX_RST_0_RESET_ON	0x10
 #define XGBE_PMA_RX_RST_0_RESET_OFF	0x00
 
+#define XGBE_PMA_PLL_CTRL_MASK		BIT(15)
+#define XGBE_PMA_PLL_CTRL_SET		BIT(15)
+#define XGBE_PMA_PLL_CTRL_CLEAR		0x0000
+
 /* Bit setting and getting macros
  *  The get macro will extract the current bit field value from within
  *  the variable

@@ -1977,12 +1977,26 @@ static void xgbe_phy_rx_reset(struct xgbe_prv_data *pdata)
 	}
 }
 
+static void xgbe_phy_pll_ctrl(struct xgbe_prv_data *pdata, bool enable)
+{
+	XMDIO_WRITE_BITS(pdata, MDIO_MMD_PMAPMD, MDIO_VEND2_PMA_MISC_CTRL0,
+			 XGBE_PMA_PLL_CTRL_MASK,
+			 enable ? XGBE_PMA_PLL_CTRL_SET
+			 : XGBE_PMA_PLL_CTRL_CLEAR);
+
+	/* Wait for command to complete */
+	usleep_range(100, 200);
+}
+
 static void xgbe_phy_perform_ratechange(struct xgbe_prv_data *pdata,
 					unsigned int cmd, unsigned int sub_cmd)
 {
 	unsigned int s0 = 0;
 	unsigned int wait;
 
+	/* Clear the PLL so that it helps in power down sequence */
+	xgbe_phy_pll_ctrl(pdata, false);
+
 	/* Log if a previous command did not complete */
 	if (XP_IOREAD_BITS(pdata, XP_DRIVER_INT_RO, STATUS)) {
 		netif_dbg(pdata, link, pdata->netdev,

@@ -2003,7 +2017,7 @@ static void xgbe_phy_perform_ratechange(struct xgbe_prv_data *pdata,
 	wait = XGBE_RATECHANGE_COUNT;
 	while (wait--) {
 		if (!XP_IOREAD_BITS(pdata, XP_DRIVER_INT_RO, STATUS))
-			return;
+			goto reenable_pll;
 
 		usleep_range(1000, 2000);
 	}

@@ -2013,6 +2027,10 @@ static void xgbe_phy_perform_ratechange(struct xgbe_prv_data *pdata,
 
 	/* Reset on error */
 	xgbe_phy_rx_reset(pdata);
+
+reenable_pll:
+	/* Re-enable the PLL control */
+	xgbe_phy_pll_ctrl(pdata, true);
 }
 
 static void xgbe_phy_rrc(struct xgbe_prv_data *pdata)

@@ -2642,7 +2642,9 @@ static int xgbe_phy_link_status(struct xgbe_prv_data *pdata, int *an_restart)
 	/* No link, attempt a receiver reset cycle */
 	if (phy_data->rrc_count++ > XGBE_RRC_FREQUENCY) {
 		phy_data->rrc_count = 0;
-		xgbe_phy_rrc(pdata);
+		/* RRC is required only if auto-negotiation is enabled */
+		if (pdata->phy.autoneg == AUTONEG_ENABLE)
+			xgbe_phy_rrc(pdata);
 	}
 
 	return 0;