diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c index 7193afc00e47..96740051cdcc 100644 --- a/drivers/net/r8169.c +++ b/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)