linux.git/net/ethtool, branch v7.2-rc1

net: ethtool: keep rtnl_lock for ops using ethtool_op_get_link()

2026-06-25T17:18:34+00:00

Breno reports following splats on mlx5:

  RTNL: assertion failed at net/core/dev.c (2241)
  WARNING: net/core/dev.c:2241 at netif_state_change+0xed/0x130, CPU#5: ethtool/1335
  RIP: 0010:netif_state_change+0xf9/0x130
  Call Trace:
    
     __linkwatch_sync_dev+0xea/0x120
     ethtool_op_get_link+0xe/0x20
     __ethtool_get_link+0x26/0x40
     linkstate_prepare_data+0x51/0x200
     ethnl_default_doit+0x213/0x470
     genl_family_rcv_msg_doit+0xdd/0x110

Looks like I missed ethtool_op_get_link() trying to sync linkwatch,
which needs rtnl_lock. Not all drivers do this - bnxt doesn't,
it just returns the link state, so add an opt-in bit.

Reported-by: Breno Leitao 
Fixes: 45079e00133e ("net: ethtool: optionally skip rtnl_lock on Netlink path for GET ops")
Acked-by: Stanislav Fomichev 
Reviewed-by: Breno Leitao 
Acked-by: Harshitha Ramamurthy 
Link: https://patch.msgid.link/20260624190439.2521219-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tls: remove tls_toe and the related driver

2026-06-12T23:43:10+00:00

The tls_toe feature and its single user (chelsio chtls) have been
unmaintained for multiple years. It also hooks into the core of the
TCP implementation, and bypasses most of the networking stack.

Signed-off-by: Sabrina Dubroca 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/1f30e73275c07bf879f547589872d0916025a52e.1781165969.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski

ethtool: tsconfig: always take rtnl_lock

2026-06-12T23:41:56+00:00

mlx5 throws ASSERT_RTNL() warnings on timestamp config, because
it tries to update features. mlx5e_hwtstamp_set() calls
netdev_update_features().

I missed this while grepping the drivers because tsconfig goes
through ndo_hwtstamp_set/get, not ethtool ops, even tho the new
uAPI is in ethtool Netlink. We could add a dedicated opt out bit
for mlx5, but NDOs were not supposed to be part of the ethtool locking
conversion in the first place.

The mlx5 features update is related to the "compressed CQE" format
which lacks timestamp, apparently. See commit c0194e2d0ef0 ("net/mlx5e:
Disable rxhash when CQE compress is enabled").

Fixes: f9a3e05114b8 ("net: ethtool: optionally skip rtnl_lock on Netlink path for SET ops")
Acked-by: Stanislav Fomichev 
Reviewed-by: Jacob Keller 
Reviewed-by: Vadim Fedorenko 
Reviewed-by: Kory Maincent 
Link: https://patch.msgid.link/20260611200355.2020663-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: ethtool: add KSZ87xx low-loss cable PHY tunables

2026-06-11T22:47:56+00:00

Introduce vendor-specific PHY tunable identifiers to control the
KSZ87xx low-loss cable erratum handling through the ethtool PHY
tunable interface.

The following tunables are added:

- a boolean "short-cable" tunable, applying a documented and
  conservative preset intended for short or low-loss Ethernet cables;

- an integer LPF bandwidth tunable, allowing advanced adjustment of the
  receiver low-pass filter bandwidth;

- an integer DSP EQ initial value tunable, allowing advanced tuning of
  the PHY equalizer initialization.

The actual behavior is implemented by the corresponding PHY and switch
drivers.

Reviewed-by: Marek Vasut 
Reviewed-by: Nicolai Buchwitz 
Signed-off-by: Fidelio Lawson 
Link: https://patch.msgid.link/20260609-ksz87xx_errata_low_loss_connections-v10-2-9ba4418cf3db@exotec.com
Signed-off-by: Jakub Kicinski

net: ethtool: optionally skip rtnl_lock on IOCTL path

2026-06-09T17:13:06+00:00

Convert the IOCTL path similarly to how we converted Netlink.
The device lookup gets a little hairy. We could take rtnl_lock
unconditionally and drop it before calling the driver (this would
avoid the reference + liveness check). But I think being able
to make progress even if rtnl is dead-locked is quite useful.

First extra concern is handling features. List all the cmds which
modify features and always take rtnl_lock. We could fold this list
into ethtool_ioctl_needs_rtnl() but seems cleaner to keep
ethtool_ioctl_needs_rtnl() driver-related. If a driver changed
features and we were not holding rtnl_lock - warn about it.
It can only happen on buggy ops locked drivers (buggy because
they should have set appropriate "I need rtnl for op X" bit).

Second wrinkle is the PHY ID hack which drops the locks while
sleeping. Convert its static "busy" variable which used to
be protected by rtnl_lock to a field in struct ethtool_netdev_state.
This feature is about identifying an adapter or a port within
a system, so being able to blink multiple LEDs at the same
time is likely not very useful in practice. But it's the simplest
fix, we can add a mutex if someone thinks a system should only
be ID'ing one port at a time.

Reviewed-by: Eric Dumazet 
Acked-by: Stanislav Fomichev 
Reviewed-by: Jacob Keller 
Link: https://patch.msgid.link/20260605002912.3456868-12-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: ethtool: ioctl: concentrate the locking

2026-06-09T17:13:06+00:00

Add another layer of helper functions to make upcoming locking
changes easier. Otherwise we'd need a pretty complex goto
structure. netdev instance lock is now taken slightly sooner
but that should not be an issue since rtnl_lock is already held,
anyway.

Reviewed-by: Eric Dumazet 
Acked-by: Stanislav Fomichev 
Reviewed-by: Jacob Keller 
Link: https://patch.msgid.link/20260605002912.3456868-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: ethtool: optionally skip rtnl_lock in RSS context handlers

2026-06-09T17:13:05+00:00

Skip rtnl_lock in RSS context handlers if device is ops-locked.
Fairly trivial conversion. bnxt needed rtnl_lock for changing
the main context but looks like additional contexts are fine
without it.

Note (for review bots?) that ethnl_ops_begin() checks whether
the device is still registered.

Reviewed-by: Eric Dumazet 
Acked-by: Stanislav Fomichev 
Reviewed-by: Jacob Keller 
Link: https://patch.msgid.link/20260605002912.3456868-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: ethtool: optionally skip rtnl_lock in ethnl_act_module_fw_flash()

2026-06-09T17:13:05+00:00

Module firmware flashing reads SFF-8024 identifier bytes via
.get_module_eeprom_by_page(). Other than that it modifies
a bit in the netdev->ethtool struct. Both should be ops-locked
at this point.

Reviewed-by: Eric Dumazet 
Acked-by: Stanislav Fomichev 
Reviewed-by: Jacob Keller 
Link: https://patch.msgid.link/20260605002912.3456868-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: ethtool: optionally skip rtnl_lock in ethnl_tsinfo_dumpit()

2026-06-09T17:13:05+00:00

ethnl_tsinfo_dumpit() iterates netdevs and per-netdev PHY topology
calling ops->get_ts_info(). Switch to the "ops compat locking"
helpers which take either rtnl_lock or instance lock, depending
on what the device needs.

Reviewed-by: Eric Dumazet 
Acked-by: Stanislav Fomichev 
Reviewed-by: Jacob Keller 
Link: https://patch.msgid.link/20260605002912.3456868-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: ethtool: optionally skip rtnl_lock in cable test handlers

2026-06-09T17:13:05+00:00

Skip rtnl_lock in cable test handlers. This is really a noop since
no ops locked device supports these.

Reviewed-by: Eric Dumazet 
Acked-by: Stanislav Fomichev 
Reviewed-by: Jacob Keller 
Link: https://patch.msgid.link/20260605002912.3456868-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski