r8169: set tc_offset only if tally counter reset isn't supported

On chip versions supporting tally counter reset we currently update
the counters after a reset although we know all counters are zero.
Skip this unnecessary step.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/526618b2-b1bf-1844-b82a-dab2df7bdc8f@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/realtek/r8169_main.c

@@ -1562,16 +1562,6 @@ static void rtl8169_do_counters(struct rtl8169_private *tp, u32 counter_cmd)
 	rtl_loop_wait_low(tp, &rtl_counters_cond, 10, 1000);
 }
 
-static void rtl8169_reset_counters(struct rtl8169_private *tp)
-{
-	/*
-	 * Versions prior to RTL_GIGA_MAC_VER_19 don't support resetting the
-	 * tally counters.
-	 */
-	if (tp->mac_version >= RTL_GIGA_MAC_VER_19)
-		rtl8169_do_counters(tp, CounterReset);
-}
-
 static void rtl8169_update_counters(struct rtl8169_private *tp)
 {
 	u8 val = RTL_R8(tp, ChipCmd);
@@ -1606,13 +1596,16 @@ static void rtl8169_init_counter_offsets(struct rtl8169_private *tp)
 	if (tp->tc_offset.inited)
 		return;
 
-	rtl8169_reset_counters(tp);
-	rtl8169_update_counters(tp);
+	if (tp->mac_version >= RTL_GIGA_MAC_VER_19) {
+		rtl8169_do_counters(tp, CounterReset);
+	} else {
+		rtl8169_update_counters(tp);
+		tp->tc_offset.tx_errors = counters->tx_errors;
+		tp->tc_offset.tx_multi_collision = counters->tx_multi_collision;
+		tp->tc_offset.tx_aborted = counters->tx_aborted;
+		tp->tc_offset.rx_missed = counters->rx_missed;
+	}
 
-	tp->tc_offset.tx_errors = counters->tx_errors;
-	tp->tc_offset.tx_multi_collision = counters->tx_multi_collision;
-	tp->tc_offset.tx_aborted = counters->tx_aborted;
-	tp->tc_offset.rx_missed = counters->rx_missed;
 	tp->tc_offset.inited = true;
 }