RE: [Intel-wired-lan] [PATCH iwl-net] ice: restore PTP Rx timestamp config after ethtool set-channels

[Nowlin, Alexander]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of Grzegorz Nitka
> Sent: Thursday, May 7, 2026 1:17 AM
> To: intel-wired-lan@xxxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx; richardcochran@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx; Loktionov, Aleksandr <aleksandr.loktionov@xxxxxxxxx>; andrew+netdev@xxxxxxx; edumazet@xxxxxxxxxx; Nguyen, Anthony L <anthony.l.nguyen@xxxxxxxxx>; Kitszel, Przemyslaw <przemyslaw.kitszel@xxxxxxxxx>; Keller, Jacob E <jacob.e.keller@xxxxxxxxx>; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx; davem@xxxxxxxxxxxxx
> Subject: [Intel-wired-lan] [PATCH iwl-net] ice: restore PTP Rx timestamp config after ethtool set-channels
> 
> When ethtool -L changes queue counts, ice_vsi_recfg_qs() closes and rebuilds the VSI, reallocating Rx rings. The newly allocated rings have ptp_rx cleared, so RX hardware timestamps are no longer attached to skb until hwtstamp configuration is applied again.
> 
> Restore timestamp mode after ice_vsi_open() in the queue reconfiguration path, matching reset/rebuild behavior and ensuring newly rebuilt Rx rings have PTP RX timestamping re-enabled.
> 
> Testing hints:
> - run ptp4l application in client synchronization mode:
> 	 ptp4l -i ethX -m -s
> - run PTP traffic
> - change queue number on ethX netdev interface:
> 	ethtool -L ethX combined new_queue_size
> - observe ptp4l output
> - expected result: no "received DELAY_REQ without timestamp" messages
> 
> Fixes: 77a781155a65 ("ice: enable receive hardware timestamping")
> Cc: stable@xxxxxxxxxxxxxxx
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@xxxxxxxxx>
> Signed-off-by: Grzegorz Nitka <grzegorz.nitka@xxxxxxxxx>
> ---
>  drivers/net/ethernet/intel/ice/ice_main.c | 6 ++++++
>  1 file changed, 6 insertions(+)

Tested-by: Alexander Nowlin <alexander.nowlin@xxxxxxxxx>