On 03.05.2021 15:31:34, Ayoub Kaanich wrote: > For the ack bit, I think we could go with the bit being a “NO_ACK” > bit, so a spy listener will set it to 1, if it receives a CAN frame, > but it does not see any node in the bus acknowledging it. This way we > preserve backward compatibility. As Vincent pointed out, the device should not receive the CAN frame that has not been acked as I do on the flexcan. And even on the mcp251xfd, where I receive the CAN frame, there's no way to tell if this frame has been acked or not. > For the FDF flag, check the MTU is not an option here, since this flag > is needed to detect normal CAN frames being transmitted on a CAN-FD > bus (The bus could be configured as CAN-FD, but the received frame > could be a normal CAN frame) > > If we are adding flags to can_frame, could we make sure it’s on the > same byte offset as the flags of can_fd_frame, since PCAP format have > no concept of MTU or struct size. Sure - Do struct can_fd_frames have a different ARP header type? Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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