From 5b24364acc04b434a633a213b34248d2b1153990 Mon Sep 17 00:00:00 2001
From: Neil Horman <nhorman@redhat.com>
Date: Mon, 29 Mar 2010 13:16:02 -0700
Subject: [PATCH] --- yaml --- r: 189183 b: refs/heads/master c:
 c0cd884af045338476b8e69a61fceb3f34ff22f1 h: refs/heads/master i:   189181:
 156cdc1298387ef6ff2af4ea5d966a57f16e33b5   189179:
 31af1e394434ae0e286f0e01997c5eda83c7a6b6   189175:
 8eeff1918ede5592e93b458b3786e5ec7823ce12   189167:
 0b53e6f651a74fb56cda5a105fabb5704f0c04d1   189151:
 f0369dee00e801de5fc6c0606f67ef6bd68c78ea   189119:
 7b2fb55c5cb2fe165abf88160145e2109bee4ba8   189055:
 a85d903278214b149205900f159dacc2534fa1f6   188927:
 7056ffa98e2521b71508afa7844e7cee4ee8f370 v: v3

---
 [refs]                    |  2 +-
 trunk/drivers/net/r8169.c | 29 ++++++++++++++++++++++++-----
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 5a8cd7ae9145..cbaf53f59de3 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 54c1a859efd9fd6cda05bc700315ba2519c14eba
+refs/heads/master: c0cd884af045338476b8e69a61fceb3f34ff22f1
diff --git a/trunk/drivers/net/r8169.c b/trunk/drivers/net/r8169.c
index 7193afc00e47..96740051cdcc 100644
--- a/trunk/drivers/net/r8169.c
+++ b/trunk/drivers/net/r8169.c
@@ -186,7 +186,12 @@ static DEFINE_PCI_DEVICE_TABLE(rtl8169_pci_tbl) = {
 
 MODULE_DEVICE_TABLE(pci, rtl8169_pci_tbl);
 
-static int rx_copybreak = 200;
+/*
+ * we set our copybreak very high so that we don't have
+ * to allocate 16k frames all the time (see note in
+ * rtl8169_open()
+ */
+static int rx_copybreak = 16383;
 static int use_dac;
 static struct {
 	u32 msg_enable;
@@ -3217,9 +3222,13 @@ static void __devexit rtl8169_remove_one(struct pci_dev *pdev)
 }
 
 static void rtl8169_set_rxbufsize(struct rtl8169_private *tp,
-				  struct net_device *dev)
+				  unsigned int mtu)
 {
-	unsigned int max_frame = dev->mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
+	unsigned int max_frame = mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
+
+	if (max_frame != 16383)
+		printk(KERN_WARNING "WARNING! Changing of MTU on this NIC"
+			"May lead to frame reception errors!\n");
 
 	tp->rx_buf_sz = (max_frame > RX_BUF_SIZE) ? max_frame : RX_BUF_SIZE;
 }
@@ -3231,7 +3240,17 @@ static int rtl8169_open(struct net_device *dev)
 	int retval = -ENOMEM;
 
 
-	rtl8169_set_rxbufsize(tp, dev);
+	/*
+	 * Note that we use a magic value here, its wierd I know
+	 * its done because, some subset of rtl8169 hardware suffers from
+	 * a problem in which frames received that are longer than
+	 * the size set in RxMaxSize register return garbage sizes
+	 * when received.  To avoid this we need to turn off filtering,
+	 * which is done by setting a value of 16383 in the RxMaxSize register
+	 * and allocating 16k frames to handle the largest possible rx value
+	 * thats what the magic math below does.
+	 */
+	rtl8169_set_rxbufsize(tp, 16383 - VLAN_ETH_HLEN - ETH_FCS_LEN);
 
 	/*
 	 * Rx and Tx desscriptors needs 256 bytes alignment.
@@ -3884,7 +3903,7 @@ static int rtl8169_change_mtu(struct net_device *dev, int new_mtu)
 
 	rtl8169_down(dev);
 
-	rtl8169_set_rxbufsize(tp, dev);
+	rtl8169_set_rxbufsize(tp, dev->mtu);
 
 	ret = rtl8169_init_ring(dev);
 	if (ret < 0)