On 12/04, Song Yoong Siang wrote: > Set tx_type to HWTSTAMP_TX_ON to enable hardware timestamping for all > outgoing packets. > > Besides, set XDP_UMEM_TX_METADATA_LEN flag to reserve tx_metadata_len bytes > of per-chunk metadata. XDP_UMEM_TX_METADATA_LEN is missing after d5e726d9143c ("xsk: Require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len"), so that make sense. Maybe add a fixes tag? And I don't see mlx5 looking at HWTSTAMP_TX anywhere in the drivers, so I'm assuming that's why I didn't need HWTSTAMP_TX_ON during my tests.. Which device are you testing against? I do see some hwts_tx_en checks in the stfmmac at least... Can you add these details to the commit message and respin? With the above addressed: Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxxx>