1
0
Fork 0
mirror of https://github.com/Ysurac/openmptcprouter.git synced 2025-02-15 04:42:02 +00:00
openmptcprouter/root/target/linux/brcm2708/patches-4.19/0134-net-lan78xx-Disable-TCP-Segmentation-Offload-TSO.patch
2019-04-22 17:10:09 +02:00

61 lines
2.3 KiB
Diff

From f36c4a3aa7c71c3fb27a1525c7008a026f8884ec 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 134/432] 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(-)
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index a5f6e53f6e13..bae45f643c15 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -439,6 +439,15 @@ 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);
@@ -3003,8 +3012,14 @@ static int lan78xx_bind(struct lan78xx_net *dev, struct usb_interface *intf)
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;
--
2.19.1