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From bce4fe9fa48df0cbbe842e80d9a520f7265b4cd4 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.org>
Date: Wed, 4 Apr 2018 16:34:24 +0100
Subject: [PATCH 5/9] net: lan78xx: Allow for VLAN headers in timeout.
The frame abort timeout being set by lan78xx_set_rx_max_frame_length
didn't account for any VLAN headers, resulting in very low
throughput if used with tagged VLANs.
Use VLAN_ETH_HLEN instead of ETH_HLEN to correct for this.
See https://github.com/raspberrypi/linux/issues/2458
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
---
drivers/net/usb/lan78xx.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 0867f7275852..5b46998a6dce 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2178,7 +2178,7 @@ static int lan78xx_change_mtu(struct net_device *netdev, int new_mtu)
if ((ll_mtu % dev->maxpacket) == 0)
return -EDOM;
- ret = lan78xx_set_rx_max_frame_length(dev, new_mtu + ETH_HLEN);
+ ret = lan78xx_set_rx_max_frame_length(dev, new_mtu + VLAN_ETH_HLEN);
netdev->mtu = new_mtu;
@@ -2467,7 +2467,8 @@ static int lan78xx_reset(struct lan78xx_net *dev)
buf |= FCT_TX_CTL_EN_;
ret = lan78xx_write_reg(dev, FCT_TX_CTL, buf);
- ret = lan78xx_set_rx_max_frame_length(dev, dev->net->mtu + ETH_HLEN);
+ ret = lan78xx_set_rx_max_frame_length(dev,
+ dev->net->mtu + VLAN_ETH_HLEN);
ret = lan78xx_read_reg(dev, MAC_RX, &buf);
buf |= MAC_RX_RXEN_;
--
2.17.0
From 6fecd97fd35e9c624d101495ca34c83b1cb23e3d Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.org>
Date: Mon, 9 Apr 2018 14:31:54 +0100
Subject: [PATCH 6/9] net: lan78xx: Request s/w csum check on VLAN tagged
packets.
There appears to be some issue in the LAN78xx where the checksum
computed on a VLAN tagged packet is incorrect, or at least not
in the form that the kernel is after. This is most easily shown
by pinging a device via a VLAN tagged interface and it will dump
out the error message and stack trace from netdev_rx_csum_fault.
It has also been seen with standard TCP and UDP packets.
Until this is fully understood, request that the network stack
computes the checksum on packets signalled as having a VLAN tag
applied.
See https://github.com/raspberrypi/linux/issues/2458
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
---
drivers/net/usb/lan78xx.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 5b46998a6dce..6b61bb21f2ae 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2920,8 +2920,12 @@ static void lan78xx_rx_csum_offload(struct lan78xx_net *dev,
struct sk_buff *skb,
u32 rx_cmd_a, u32 rx_cmd_b)
{
+ /* Checksum offload appears to be flawed if used with VLANs.
+ * Elect for sw checksum check instead.
+ */
if (!(dev->net->features & NETIF_F_RXCSUM) ||
- unlikely(rx_cmd_a & RX_CMD_A_ICSM_)) {
+ unlikely(rx_cmd_a & RX_CMD_A_ICSM_) ||
+ (rx_cmd_a & RX_CMD_A_FVTG_)) {
skb->ip_summed = CHECKSUM_NONE;
} else {
skb->csum = ntohs((u16)(rx_cmd_b >> RX_CMD_B_CSUM_SHIFT_));
--
2.17.0
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