r8169: disable default rx interrupt coalescing on RTL8168

hkallweit · davem330 · commit 288ac524cf70 · 2019-03-30T11:04:54.000-07:00
It was reported that re-introducing ASPM, in combination with RX interrupt coalescing, results in significantly increased packet latency, see [0]. Disabling ASPM or RX interrupt coalescing fixes the issue. Therefore change the driver's default to disable RX interrupt coalescing. Users still have the option to enable RX coalescing via ethtool. [0] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=925496 Fixes: a99790b ("r8169: Reinstate ASPM Support") Reported-by: Mike Crowe <mac@mcrowe.com> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
@@ -5460,7 +5460,7 @@ static void rtl_hw_start_8168(struct rtl8169_private *tp)
 	tp->cp_cmd |= PktCntrDisable | INTT_1;
 	RTL_W16(tp, CPlusCmd, tp->cp_cmd);
 
-	RTL_W16(tp, IntrMitigate, 0x5151);
+	RTL_W16(tp, IntrMitigate, 0x5100);
 
 	/* Work around for RxFIFO overflow. */
 	if (tp->mac_version == RTL_GIGA_MAC_VER_11) {
