r8169: fix jumbo packet handling on resume from suspend

Mariusz reported that invalid packets are sent after resume from
suspend if jumbo packets are active. It turned out that his BIOS
resets chip settings to non-jumbo on resume. Most chip settings are
re-initialized on resume from suspend by calling rtl_hw_start(),
so let's add configuring jumbo to this function.
There's nothing wrong with the commit marked as fixed, it's just
the first one where the patch applies cleanly.

Fixes: 7366016 ("r8169: read common register for PCI commit")
Reported-by: Mariusz Bialonczyk <manio@skyboo.net>
Tested-by: Mariusz Bialonczyk <manio@skyboo.net>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

drivers/net/ethernet/realtek/r8169_main.c

@@ -4146,6 +4146,14 @@ static void rtl_hw_jumbo_disable(struct rtl8169_private *tp)
 	rtl_lock_config_regs(tp);
 }
 
+static void rtl_jumbo_config(struct rtl8169_private *tp, int mtu)
+{
+	if (mtu > ETH_DATA_LEN)
+		rtl_hw_jumbo_enable(tp);
+	else
+		rtl_hw_jumbo_disable(tp);
+}
+
 DECLARE_RTL_COND(rtl_chipcmd_cond)
 {
 	return RTL_R8(tp, ChipCmd) & CmdReset;
@@ -4442,11 +4450,6 @@ static void rtl8168g_set_pause_thresholds(struct rtl8169_private *tp,
 static void rtl_hw_start_8168bb(struct rtl8169_private *tp)
 {
 	RTL_W8(tp, Config3, RTL_R8(tp, Config3) & ~Beacon_en);
-
-	if (tp->dev->mtu <= ETH_DATA_LEN) {
-		rtl_tx_performance_tweak(tp, PCI_EXP_DEVCTL_READRQ_4096B |
-					 PCI_EXP_DEVCTL_NOSNOOP_EN);
-	}
 }
 
 static void rtl_hw_start_8168bef(struct rtl8169_private *tp)
@@ -4462,9 +4465,6 @@ static void __rtl_hw_start_8168cp(struct rtl8169_private *tp)
 
 	RTL_W8(tp, Config3, RTL_R8(tp, Config3) & ~Beacon_en);
 
-	if (tp->dev->mtu <= ETH_DATA_LEN)
-		rtl_tx_performance_tweak(tp, PCI_EXP_DEVCTL_READRQ_4096B);
-
 	rtl_disable_clock_request(tp);
 }
 
@@ -4490,9 +4490,6 @@ static void rtl_hw_start_8168cp_2(struct rtl8169_private *tp)
 	rtl_set_def_aspm_entry_latency(tp);
 
 	RTL_W8(tp, Config3, RTL_R8(tp, Config3) & ~Beacon_en);
-
-	if (tp->dev->mtu <= ETH_DATA_LEN)
-		rtl_tx_performance_tweak(tp, PCI_EXP_DEVCTL_READRQ_4096B);
 }
 
 static void rtl_hw_start_8168cp_3(struct rtl8169_private *tp)
@@ -4503,9 +4500,6 @@ static void rtl_hw_start_8168cp_3(struct rtl8169_private *tp)
 
 	/* Magic. */
 	RTL_W8(tp, DBG_REG, 0x20);
-
-	if (tp->dev->mtu <= ETH_DATA_LEN)
-		rtl_tx_performance_tweak(tp, PCI_EXP_DEVCTL_READRQ_4096B);
 }
 
 static void rtl_hw_start_8168c_1(struct rtl8169_private *tp)
@@ -4611,9 +4605,6 @@ static void rtl_hw_start_8168e_1(struct rtl8169_private *tp)
 
 	rtl_ephy_init(tp, e_info_8168e_1);
 
-	if (tp->dev->mtu <= ETH_DATA_LEN)
-		rtl_tx_performance_tweak(tp, PCI_EXP_DEVCTL_READRQ_4096B);
-
 	rtl_disable_clock_request(tp);
 
 	/* Reset tx FIFO pointer */
@@ -4636,9 +4627,6 @@ static void rtl_hw_start_8168e_2(struct rtl8169_private *tp)
 
 	rtl_ephy_init(tp, e_info_8168e_2);
 
-	if (tp->dev->mtu <= ETH_DATA_LEN)
-		rtl_tx_performance_tweak(tp, PCI_EXP_DEVCTL_READRQ_4096B);
-
 	rtl_eri_write(tp, 0xc0, ERIAR_MASK_0011, 0x0000);
 	rtl_eri_write(tp, 0xb8, ERIAR_MASK_0011, 0x0000);
 	rtl_set_fifo_size(tp, 0x10, 0x10, 0x02, 0x06);
@@ -5485,6 +5473,8 @@ static void rtl_hw_start(struct  rtl8169_private *tp)
 	rtl_set_rx_tx_desc_registers(tp);
 	rtl_lock_config_regs(tp);
 
+	rtl_jumbo_config(tp, tp->dev->mtu);
+
 	/* Initially a 10 us delay. Turned it into a PCI commit. - FR */
 	RTL_R16(tp, CPlusCmd);
 	RTL_W8(tp, ChipCmd, CmdTxEnb | CmdRxEnb);
@@ -5498,10 +5488,7 @@ static int rtl8169_change_mtu(struct net_device *dev, int new_mtu)
 {
 	struct rtl8169_private *tp = netdev_priv(dev);
 
-	if (new_mtu > ETH_DATA_LEN)
-		rtl_hw_jumbo_enable(tp);
-	else
-		rtl_hw_jumbo_disable(tp);
+	rtl_jumbo_config(tp, new_mtu);
 
 	dev->mtu = new_mtu;
 	netdev_update_features(dev);