> -----Original Message-----
> From: Petr Oros <[email protected]>
> Sent: Friday, October 23, 2026 9:03 AM
> To: [email protected]
> Cc: Oros, Petr <[email protected]>; Nguyen, Anthony L
> <[email protected]>; Kitszel, Przemyslaw
> <[email protected]>; Andrew Lunn <[email protected]>;
> David S. Miller <[email protected]>; Eric Dumazet
> <[email protected]>; Jakub Kicinski <[email protected]>; Paolo Abeni
> <[email protected]>; Sebastian Andrzej Siewior <[email protected]>;
> Clark Williams <[email protected]>; Steven Rostedt
> <[email protected]>; Ertman, David M <[email protected]>;
> Mateusz Palczewski <[email protected]>; Leon Romanovsky
> <[email protected]>; Rafal Rogalski <[email protected]>; Shiraz
> Saleem <[email protected]>; Loktionov, Aleksandr
> <[email protected]>; [email protected];
> [email protected]; [email protected]
> Subject: [PATCH iwl-net v2 4/5] ice: do not block on the aux device lock
> in ethtool set_channels
>
> ice_set_channels() takes the auxiliary device lock to test whether the
> RDMA driver is bound, and ethtool ops run with the RTNL lock held. This
> is the same inversion against the RDMA auxiliary probe as the one fixed
> in ice_send_event_to_aux(), reached through a different caller.
>
> Use device_trylock() and report the device as busy when it fails. The
> existing diagnostic is not reused, a contended lock does not mean the
> RDMA driver is bound. It is a netdev_dbg(), the condition is transient
> and userspace already learns about it from -EBUSY.
>
> Fixes: a6a0974aae42 ("ice: Prevent set_channel from changing queues
> while RDMA active")
> Signed-off-by: Petr Oros <[email protected]>
> ---
> v2:
> - rebased on the new patches 1 and 2, the trylock now sits inside the
> pointer test done under adev_mutex
>
> v1: https://lore.kernel.org/all/20261019065301.3983537-3-
> [email protected]/
> ---
> drivers/net/ethernet/intel/ice/ice_ethtool.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c
> b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> index 5482a64c81c95a..dbc662d6233957 100644
> --- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
> +++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> @@ -3947,7 +3947,11 @@ static int ice_set_channels(struct net_device
> *dev, struct ethtool_channels *ch)
> mutex_lock(&pf->adev_mutex);
> adev = pf->cdev_info->adev;
> if (adev) {
> - device_lock(&adev->dev);
> + if (!device_trylock(&adev->dev)) {
> + mutex_unlock(&pf->adev_mutex);
> + netdev_dbg(dev, "RDMA auxiliary device is
> busy, try again\n");
> + return -EBUSY;
> + }
> locked = true;
> if (adev->dev.driver) {
> netdev_err(dev, "Cannot change channels when
> RDMA is active\n");
> --
> 2.56.0
Reviewed-by: Aleksandr Loktionov <[email protected]>
