r8169: add helper rtl_enable_rxdvgate

Add a helper for setting RXDV_GATED_EN, the 2ms delay is copied from
the vendor driver.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/realtek/r8169_main.c

@@ -2494,6 +2494,12 @@ DECLARE_RTL_COND(rtl_txcfg_empty_cond)
 	return RTL_R32(tp, TxConfig) & TXCFG_EMPTY;
 }
 
+static void rtl_enable_rxdvgate(struct rtl8169_private *tp)
+{
+	RTL_W32(tp, MISC, RTL_R32(tp, MISC) | RXDV_GATED_EN);
+	fsleep(2000);
+}
+
 static void rtl8169_hw_reset(struct rtl8169_private *tp)
 {
 	/* Disable interrupts */
@@ -5131,7 +5137,7 @@ static int r8169_mdio_register(struct rtl8169_private *tp)
 
 static void rtl_hw_init_8168g(struct rtl8169_private *tp)
 {
-	RTL_W32(tp, MISC, RTL_R32(tp, MISC) | RXDV_GATED_EN);
+	rtl_enable_rxdvgate(tp);
 
 	if (!rtl_loop_wait_high(tp, &rtl_txcfg_empty_cond, 100, 42))
 		return;
@@ -5152,7 +5158,7 @@ static void rtl_hw_init_8168g(struct rtl8169_private *tp)
 
 static void rtl_hw_init_8125(struct rtl8169_private *tp)
 {
-	RTL_W32(tp, MISC, RTL_R32(tp, MISC) | RXDV_GATED_EN);
+	rtl_enable_rxdvgate(tp);
 
 	if (!rtl_loop_wait_high(tp, &rtl_rxtx_empty_cond, 100, 42))
 		return;