[PATCH net-next v2 0/5] net: thunderbolt: Various improvements

[PATCH net-next v2 0/5] net: thunderbolt: Various improvements

[Mika Westerberg]

Hi all,

This series improves the Thunderbolt networking driver so that it should
work with the bonding driver. I added also possibility of channing MTU
which is sometimes needed, and was part of the original driver.

The discussion that started this patch series can be read below:

  https://lore.kernel.org/netdev/CAFJzfF9N4Hak23sc-zh0jMobbkjK7rg4odhic1DQ1cC+=MoQoA@mail.gmail.com/

The previous version of the series can be seen here:

  v1: https://lore.kernel.org/netdev/20251127131521.2580237-1-mika.westerberg@linux.intel.com/

Changes from the previous version:

  - Add SPEED_80000
  - Add support for SPEED_80000 for ethtool and 3ad bonding driver
  - Use SPEED_80000 with the USB4 v2 symmetric link
  - Fill blank for supported and advertising.

Ian MacDonald (1):
  net: thunderbolt: Allow reading link settings

Mika Westerberg (4):
  net: thunderbolt: Allow changing MAC address of the device
  net: thunderbolt: Allow changing MTU of the device
  net: ethtool: Add define for SPEED_80000
  bonding: 3ad: Add support for SPEED_80000

 drivers/net/bonding/bond_3ad.c |  6 ++++
 drivers/net/thunderbolt/main.c | 64 ++++++++++++++++++++++++++++++++++
 include/uapi/linux/ethtool.h   |  1 +
 3 files changed, 71 insertions(+)

-- 
2.50.1

[PATCH net-next v2 1/5] net: thunderbolt: Allow changing MAC address of the device

[Mika Westerberg]

The MAC address we use is based on a suggestion in the USB4 Inter-domain
spec but it is not really used in the USB4NET protocol. It is more
targeted for the upper layers of the network stack. There is no reason
why it should not be changed by the userspace for example if needed for
bonding.

Reported-by: Ian MacDonald <ian@netstatz.com>
Closes: https://lore.kernel.org/netdev/CAFJzfF9N4Hak23sc-zh0jMobbkjK7rg4odhic1DQ1cC+=MoQoA@mail.gmail.com/
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/net/thunderbolt/main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/thunderbolt/main.c b/drivers/net/thunderbolt/main.c
index dcaa62377808..57b226afeb84 100644
--- a/drivers/net/thunderbolt/main.c
+++ b/drivers/net/thunderbolt/main.c
@@ -1261,6 +1261,7 @@ static const struct net_device_ops tbnet_netdev_ops = {
 	.ndo_open = tbnet_open,
 	.ndo_stop = tbnet_stop,
 	.ndo_start_xmit = tbnet_start_xmit,
+	.ndo_set_mac_address = eth_mac_addr,
 	.ndo_get_stats64 = tbnet_get_stats64,
 };
 
@@ -1281,6 +1282,9 @@ static void tbnet_generate_mac(struct net_device *dev)
 	hash = jhash2((u32 *)xd->local_uuid, 4, hash);
 	addr[5] = hash & 0xff;
 	eth_hw_addr_set(dev, addr);
+
+	/* Allow changing it if needed */
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
 }
 
 static int tbnet_probe(struct tb_service *svc, const struct tb_service_id *id)
-- 
2.50.1

[PATCH net-next v2 2/5] net: thunderbolt: Allow changing MTU of the device

[Mika Westerberg]

In some cases it is useful to be able to use different MTU than the
default one. Especially when dealing against non-Linux networking stack.
For this reason add possibility to change the MTU of the device.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/net/thunderbolt/main.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/thunderbolt/main.c b/drivers/net/thunderbolt/main.c
index 57b226afeb84..20bac55a3e20 100644
--- a/drivers/net/thunderbolt/main.c
+++ b/drivers/net/thunderbolt/main.c
@@ -1257,12 +1257,23 @@ static void tbnet_get_stats64(struct net_device *dev,
 	stats->rx_missed_errors = net->stats.rx_missed_errors;
 }
 
+static int tbnet_change_mtu(struct net_device *dev, int new_mtu)
+{
+	/* Keep the MTU within supported range */
+	if (new_mtu < 68 || new_mtu > (TBNET_MAX_MTU - ETH_HLEN))
+		return -EINVAL;
+
+	dev->mtu = new_mtu;
+	return 0;
+}
+
 static const struct net_device_ops tbnet_netdev_ops = {
 	.ndo_open = tbnet_open,
 	.ndo_stop = tbnet_stop,
 	.ndo_start_xmit = tbnet_start_xmit,
 	.ndo_set_mac_address = eth_mac_addr,
 	.ndo_get_stats64 = tbnet_get_stats64,
+	.ndo_change_mtu	= tbnet_change_mtu,
 };
 
 static void tbnet_generate_mac(struct net_device *dev)
-- 
2.50.1

[PATCH net-next v2 3/5] net: ethtool: Add define for SPEED_80000

[Mika Westerberg]

USB4 v2 link used in peer-to-peer networking is symmetric 80 Gbps so in
order to support reading this link speed, add it to ethtool.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 include/uapi/linux/ethtool.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index eb7ff2602fbb..181243a2d700 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -2190,6 +2190,7 @@ enum ethtool_link_mode_bit_indices {
 #define SPEED_40000		40000
 #define SPEED_50000		50000
 #define SPEED_56000		56000
+#define SPEED_80000		80000
 #define SPEED_100000		100000
 #define SPEED_200000		200000
 #define SPEED_400000		400000
-- 
2.50.1

[PATCH net-next v2 4/5] bonding: 3ad: Add support for SPEED_80000

[Mika Westerberg]

Add support for ethtool SPEED_80000. This is needed to allow
Thunderbolt/USB4 networking driver to be used with the bonding driver.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/net/bonding/bond_3ad.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index 1a8de2bf8655..e5e9c7207309 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -72,6 +72,7 @@ enum ad_link_speed_type {
 	AD_LINK_SPEED_40000MBPS,
 	AD_LINK_SPEED_50000MBPS,
 	AD_LINK_SPEED_56000MBPS,
+	AD_LINK_SPEED_80000MBPS,
 	AD_LINK_SPEED_100000MBPS,
 	AD_LINK_SPEED_200000MBPS,
 	AD_LINK_SPEED_400000MBPS,
@@ -297,6 +298,7 @@ static inline int __check_agg_selection_timer(struct port *port)
  *     %AD_LINK_SPEED_40000MBPS
  *     %AD_LINK_SPEED_50000MBPS
  *     %AD_LINK_SPEED_56000MBPS
+ *     %AD_LINK_SPEED_80000MBPS
  *     %AD_LINK_SPEED_100000MBPS
  *     %AD_LINK_SPEED_200000MBPS
  *     %AD_LINK_SPEED_400000MBPS
@@ -365,6 +367,10 @@ static u16 __get_link_speed(struct port *port)
 			speed = AD_LINK_SPEED_56000MBPS;
 			break;
 
+		case SPEED_80000:
+			speed = AD_LINK_SPEED_80000MBPS;
+			break;
+
 		case SPEED_100000:
 			speed = AD_LINK_SPEED_100000MBPS;
 			break;
-- 
2.50.1

[PATCH net-next v2 5/5] net: thunderbolt: Allow reading link settings

[Mika Westerberg]

From: Ian MacDonald <ian@netstatz.com>

In order to use Thunderbolt networking as part of bonding device it
needs to support ->get_link_ksettings() ethtool operation, so that the
bonding driver can read the link speed and the related attributes. Add
support for this to the driver.

Signed-off-by: Ian MacDonald <ian@netstatz.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/net/thunderbolt/main.c | 49 ++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/drivers/net/thunderbolt/main.c b/drivers/net/thunderbolt/main.c
index 20bac55a3e20..74160d14cf46 100644
--- a/drivers/net/thunderbolt/main.c
+++ b/drivers/net/thunderbolt/main.c
@@ -10,6 +10,7 @@
  */
 
 #include <linux/atomic.h>
+#include <linux/ethtool.h>
 #include <linux/highmem.h>
 #include <linux/if_vlan.h>
 #include <linux/jhash.h>
@@ -1276,6 +1277,53 @@ static const struct net_device_ops tbnet_netdev_ops = {
 	.ndo_change_mtu	= tbnet_change_mtu,
 };
 
+static int tbnet_get_link_ksettings(struct net_device *dev,
+				    struct ethtool_link_ksettings *cmd)
+{
+	const struct tbnet *net = netdev_priv(dev);
+	const struct tb_xdomain *xd = net->xd;
+	int speed;
+
+	ethtool_link_ksettings_zero_link_mode(cmd, supported);
+	ethtool_link_ksettings_zero_link_mode(cmd, advertising);
+
+	/* Figure out the current link speed and width */
+	switch (xd->link_speed) {
+	case 40:
+		speed = SPEED_80000;
+		break;
+
+	case 20:
+		if (xd->link_width == 2)
+			speed = SPEED_40000;
+		else
+			speed = SPEED_20000;
+		break;
+
+	case 10:
+		if (xd->link_width == 2) {
+			speed = SPEED_20000;
+			break;
+		}
+		fallthrough;
+
+	default:
+		speed = SPEED_10000;
+		break;
+	}
+
+	cmd->base.speed = speed;
+	cmd->base.duplex = DUPLEX_FULL;
+	cmd->base.autoneg = AUTONEG_DISABLE;
+	cmd->base.port = PORT_OTHER;
+
+	return 0;
+}
+
+static const struct ethtool_ops tbnet_ethtool_ops = {
+	.get_link_ksettings = tbnet_get_link_ksettings,
+};
+
 static void tbnet_generate_mac(struct net_device *dev)
 {
 	const struct tbnet *net = netdev_priv(dev);
@@ -1326,6 +1374,7 @@ static int tbnet_probe(struct tb_service *svc, const struct tb_service_id *id)
 
 	strcpy(dev->name, "thunderbolt%d");
 	dev->netdev_ops = &tbnet_netdev_ops;
+	dev->ethtool_ops = &tbnet_ethtool_ops;
 
 	/* ThunderboltIP takes advantage of TSO packets but instead of
 	 * segmenting them we just split the packet into Thunderbolt
-- 
2.50.1

Re: [PATCH net-next v2 0/5] net: thunderbolt: Various improvements

[Simon Horman]

On Mon, Dec 15, 2025 at 01:11:04PM +0100, Mika Westerberg wrote:
> Hi all,
> 
> This series improves the Thunderbolt networking driver so that it should
> work with the bonding driver. I added also possibility of channing MTU
> which is sometimes needed, and was part of the original driver.
> 
> The discussion that started this patch series can be read below:
> 
>   https://lore.kernel.org/netdev/CAFJzfF9N4Hak23sc-zh0jMobbkjK7rg4odhic1DQ1cC+=MoQoA@mail.gmail.com/
> 
> The previous version of the series can be seen here:
> 
>   v1: https://lore.kernel.org/netdev/20251127131521.2580237-1-mika.westerberg@linux.intel.com/

...

## Form letter - net-next-closed

net-next is currently closed for new drivers, features, code refactoring and
optimizations. We are currently accepting bug fixes only.

net-next was closed when the merge window for v6.19 began. And due to a
combination of the travel commitments of the maintainers, and the holiday
season, net-next will not re-open until after 2nd January.

Please repost when net-next reopens.

RFC patches sent for review only are welcome at any time.

Thanks for your understanding.

See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle

-- 
pw-bot: defer