net: phy: realtek: add delay to fix RXC generation issue

PHY will delay about 11.5ms to generate RXC clock when switching from
power down to normal operation. Read/write registers would also cause RXC
become unstable and stop for a while during this process. Realtek engineer
suggests 15ms or more delay can workaround this issue.
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/realtek.c

@@ -410,6 +410,19 @@ static int rtl8211f_config_init(struct phy_device *phydev)
 	return genphy_soft_reset(phydev);
 }
 
+static int rtl821x_resume(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = genphy_resume(phydev);
+	if (ret < 0)
+		return ret;
+
+	msleep(20);
+
+	return 0;
+}
+
 static int rtl8211e_config_init(struct phy_device *phydev)
 {
 	int ret = 0, oldpage;
@@ -906,7 +919,7 @@ static struct phy_driver realtek_drvs[] = {
 		.config_intr	= &rtl8211f_config_intr,
 		.handle_interrupt = rtl8211f_handle_interrupt,
 		.suspend	= genphy_suspend,
-		.resume		= genphy_resume,
+		.resume		= rtl821x_resume,
 		.read_page	= rtl821x_read_page,
 		.write_page	= rtl821x_write_page,
 	}, {