On 14.04.23 17:49, Song Yoong Siang wrote: > igc_configure_rx_ring() function will be called as part of XDP program > setup. If Rx hardware timestamp is enabled prio to XDP program setup, > this timestamp enablement will be overwritten when buffer size is > written into SRRCTL register. > Hi all, I'm actually searching for the root cause of a similar problem (RX timestamp lost) that I can reproduce here, but the setup is slightly different. The setup: - igc driver - i225/226 network card - When starting to transmit frames using XDP with zero copy enabled another application (ptp4l) complains about missing RX timestamps - Loading the XDP program has already been removed (not needed for TX only) - ptp4l is using the traditional socket API - The RX timestamps seem to come back once we stop sending frames using XDP The "zero copy support" enabled part is important. If ZC support is not requested everything works fine. Any ideas? Best regards, Florian