lede/target/linux/bcm27xx/patches-5.4/950-0117-net-lan78xx-Disable-TCP-Segmentation-Offload-TSO.patch
AmadeusGhost 404209f6c4
kernel: bump to 4.14.193, 4.19.138, 5.4.59 (#5350)
kernel: bump to 4.14.193, 4.19.138, 5.4.59 (#5350)
  431fb8c mac80211: add AQL improvements
  6bdd4c9 mac80211: add missing backports for building with 4.14 kernels
  0106820 mac80211: add missing return code checks in AQL improvements
  e7f7101 mac80211: rework encapsulation offload support

[package]
  base-files: add function for generating random MAC
  dnsmasq: abort dhcp_check on interface state
  boot: sync upstream source code
  ath10k-ct-firmware/mt76/sch_cake: update to latest git HEAD

[script]
  download: add China Mirror Station

[target]
  Sync: arc770, ath79, bcm63xx, kirkwood, lantiq, layerscape,
        mediatek, mvebu, octeon, oxnas, pistachio, uml
  Sync most of the target patches.

Run-compiled-on: ipq40xx (4.19 & 5.4), ramips
2020-08-26 11:31:50 +08:00

57 lines
2.1 KiB
Diff

From b34a93b528f08401835259c477ade49730fc1baf Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.org>
Date: Wed, 13 Jun 2018 15:21:10 +0100
Subject: [PATCH] net: lan78xx: Disable TCP Segmentation Offload (TSO)
TSO seems to be having issues when packets are dropped and the
remote end uses Selective Acknowledge (SACK) to denote that
data is missing. The missing data is never resent, so the
connection eventually stalls.
There is a module parameter of enable_tso added to allow
further debugging without forcing a rebuild of the kernel.
https://github.com/raspberrypi/linux/issues/2449
https://github.com/raspberrypi/linux/issues/2482
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
---
drivers/net/usb/lan78xx.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -425,6 +425,15 @@ static int msg_level = -1;
module_param(msg_level, int, 0);
MODULE_PARM_DESC(msg_level, "Override default message level");
+/* TSO seems to be having some issue with Selective Acknowledge (SACK) that
+ * results in lost data never being retransmitted.
+ * Disable it by default now, but adds a module parameter to enable it for
+ * debug purposes (the full cause is not currently understood).
+ */
+static bool enable_tso;
+module_param(enable_tso, bool, 0644);
+MODULE_PARM_DESC(enable_tso, "Enables TCP segmentation offload");
+
static int lan78xx_read_reg(struct lan78xx_net *dev, u32 index, u32 *data)
{
u32 *buf = kmalloc(sizeof(u32), GFP_KERNEL);
@@ -2925,8 +2934,14 @@ static int lan78xx_bind(struct lan78xx_n
if (DEFAULT_RX_CSUM_ENABLE)
dev->net->features |= NETIF_F_RXCSUM;
- if (DEFAULT_TSO_CSUM_ENABLE)
- dev->net->features |= NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_SG;
+ if (DEFAULT_TSO_CSUM_ENABLE) {
+ dev->net->features |= NETIF_F_SG;
+ /* Use module parameter to control TCP segmentation offload as
+ * it appears to cause issues.
+ */
+ if (enable_tso)
+ dev->net->features |= NETIF_F_TSO | NETIF_F_TSO6;
+ }
if (DEFAULT_VLAN_RX_OFFLOAD)
dev->net->features |= NETIF_F_HW_VLAN_CTAG_RX;