Re: PROBLEM: too much RX drop packets on kernel 2.6.26 and 2.6.27.x

[Marc Dietrich]

Hi Terleev,

On Friday 24 October 2008 10:00:07 Terleev Roman wrote:
> hello, linux-kernel.
>
> [1.] One line summary of the problem:
> too much RX drop packets
>
> [2.] Full description of the problem/report:
> "Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit
> Ethernet controller" - network is up and working, but too much more drop
> packets:
>
> working int:
> #ifconfig eth0
> eth0      Link encap:Ethernet  HWaddr 00:1F:D0:5C:1A:5A
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:7323 errors:0 dropped:7564458177891 overruns:0 frame:0
>           TX packets:8388 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:688493 (672.3 KiB)  TX bytes:5088993 (4.8 MiB)
>           Interrupt:251 Base address:0x4000

does the attached patch (from git-net) fix it?

To NetDev: Is this already in a stable-branch?

Marc


From 422f23adb15141fffbba4c2579b26c59fabc3537 Mon Sep 17 00:00:00 2001
From: Francois Romieu <romieu@xxxxxxxxxxxxx>
Date: Thu, 21 Aug 2008 23:20:40 +0200
Subject: [PATCH] r8169: fix RxMissed register access

- the register location is defined for the 8169 chipset only
- only the lower 3 bytes of the register are valid

Signed-off-by: Francois Romieu <romieu@xxxxxxxxxxxxx>
Cc: Edward Hsu <edward_hsu@xxxxxxxxxxxxxx>
---
 drivers/net/r8169.c |   22 ++++++++++------------
 1 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index 0f6f974..4190ee7 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -2099,8 +2099,6 @@ static void rtl_hw_start_8168(struct net_device *dev)
 
 	RTL_R8(IntrMask);
 
-	RTL_W32(RxMissed, 0);
-
 	rtl_set_rx_mode(dev);
 
 	RTL_W8(ChipCmd, CmdTxEnb | CmdRxEnb);
@@ -2143,8 +2141,6 @@ static void rtl_hw_start_8101(struct net_device *dev)
 
 	RTL_R8(IntrMask);
 
-	RTL_W32(RxMissed, 0);
-
 	rtl_set_rx_mode(dev);
 
 	RTL_W8(ChipCmd, CmdTxEnb | CmdRxEnb);
@@ -2922,6 +2918,17 @@ static int rtl8169_poll(struct napi_struct *napi, int budget)
 	return work_done;
 }
 
+static void rtl8169_rx_missed(struct net_device *dev, void __iomem *ioaddr)
+{
+	struct rtl8169_private *tp = netdev_priv(dev);
+
+	if (tp->mac_version > RTL_GIGA_MAC_VER_06)
+		return;
+
+	dev->stats.rx_missed_errors += (RTL_R32(RxMissed) & 0xffffff);
+	RTL_W32(RxMissed, 0);
+}
+
 static void rtl8169_down(struct net_device *dev)
 {
 	struct rtl8169_private *tp = netdev_priv(dev);
@@ -2939,9 +2946,7 @@ core_down:
 
 	rtl8169_asic_down(ioaddr);
 
-	/* Update the error counts. */
-	dev->stats.rx_missed_errors += RTL_R32(RxMissed);
-	RTL_W32(RxMissed, 0);
+	rtl8169_rx_missed(dev, ioaddr);
 
 	spin_unlock_irq(&tp->lock);
 
@@ -3063,8 +3068,7 @@ static struct net_device_stats *rtl8169_get_stats(struct net_device *dev)
 
 	if (netif_running(dev)) {
 		spin_lock_irqsave(&tp->lock, flags);
-		dev->stats.rx_missed_errors += RTL_R32(RxMissed);
-		RTL_W32(RxMissed, 0);
+		rtl8169_rx_missed(dev, ioaddr);
 		spin_unlock_irqrestore(&tp->lock, flags);
 	}
 
@@ -3089,8 +3093,7 @@ static int rtl8169_suspend(struct pci_dev *pdev, pm_message_t state)
 
 	rtl8169_asic_down(ioaddr);
 
-	dev->stats.rx_missed_errors += RTL_R32(RxMissed);
-	RTL_W32(RxMissed, 0);
+	rtl8169_rx_missed(dev, ioaddr);
 
 	spin_unlock_irq(&tp->lock);