bcm27xx: add linux 5.4 support

Tested on bcm2710 (Raspberry Pi 3B).

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0117-net-lan78xx-Disable-TCP-Segmentation-Offload-TSO.patch b/target/linux/bcm27xx/patches-5.4/950-0117-net-lan78xx-Disable-TCP-Segmentation-Offload-TSO.patch
new file mode 100644
index 0000000000..be6173c930
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0117-net-lan78xx-Disable-TCP-Segmentation-Offload-TSO.patch
@@ -0,0 +1,56 @@
+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
+@@ -429,6 +429,15 @@ 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);
+@@ -2995,8 +3004,14 @@ 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;