diff --git a/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt b/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt
index 42a248301615..e22d8cfea687 100644
--- a/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt
+++ b/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt
@@ -57,6 +57,13 @@ KSZ9031:
       - txd2-skew-ps : Skew control of TX data 2 pad
       - txd3-skew-ps : Skew control of TX data 3 pad
 
+    - micrel,force-master:
+        Boolean, force phy to master mode. Only set this option if the phy
+        reference clock provided at CLK125_NDO pin is used as MAC reference
+        clock because the clock jitter in slave mode is to high (errata#2).
+        Attention: The link partner must be configurable as slave otherwise
+        no link will be established.
+
 Examples:
 
 	mdio {
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index f41b224a9cdb..ab195f0916d6 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -573,9 +573,40 @@ static int ksz9031_config_init(struct phy_device *phydev)
 		ksz9031_of_load_skew_values(phydev, of_node,
 				MII_KSZ9031RN_TX_DATA_PAD_SKEW, 4,
 				tx_data_skews, 4);
+
+		/* Silicon Errata Sheet (DS80000691D or DS80000692D):
+		 * When the device links in the 1000BASE-T slave mode only,
+		 * the optional 125MHz reference output clock (CLK125_NDO)
+		 * has wide duty cycle variation.
+		 *
+		 * The optional CLK125_NDO clock does not meet the RGMII
+		 * 45/55 percent (min/max) duty cycle requirement and therefore
+		 * cannot be used directly by the MAC side for clocking
+		 * applications that have setup/hold time requirements on
+		 * rising and falling clock edges.
+		 *
+		 * Workaround:
+		 * Force the phy to be the master to receive a stable clock
+		 * which meets the duty cycle requirement.
+		 */
+		if (of_property_read_bool(of_node, "micrel,force-master")) {
+			result = phy_read(phydev, MII_CTRL1000);
+			if (result < 0)
+				goto err_force_master;
+
+			/* enable master mode, config & prefer master */
+			result |= CTL1000_ENABLE_MASTER | CTL1000_AS_MASTER;
+			result = phy_write(phydev, MII_CTRL1000, result);
+			if (result < 0)
+				goto err_force_master;
+		}
 	}
 
 	return ksz9031_center_flp_timing(phydev);
+
+err_force_master:
+	phydev_err(phydev, "failed to force the phy to master mode\n");
+	return result;
 }
 
 #define KSZ8873MLL_GLOBAL_CONTROL_4	0x06