Marc Kleine-Budde [off-list ref] 於 2025年3月28日 週五 下午3:22寫道：

quoted

quoted

quoted

quoted

quoted

quoted

quoted

quoted

quoted

+     priv->can.clock.freq = can_clk;
+     priv->can.bittiming_const = &nct6694_can_bittiming_nominal_const;
+     priv->can.data_bittiming_const = &nct6694_can_bittiming_data_const;
+     priv->can.do_set_mode = nct6694_can_set_mode;
+     priv->can.do_get_berr_counter = nct6694_can_get_berr_counter;
+     priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+             CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING |
+             CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO;

Does your device run in CAN-FD mode all the time? If so, please use
can_set_static_ctrlmode() to set it after priv->can.ctrlmode_supported
and remove CAN_CTRLMODE_FD from ctrlmode_supported.

Our device is designed to allow users to dynamically switch between
Classical CAN and CAN-FD mode via ip link set ... fd on/off.
Therefore, CAN_CTRLMODE_FD needs to remain in ctrlmode_supported, and
can_set_static_ctrlmode() is not suitable in this case.
Please let me know if you have any concerns about this approach.

Where do you evaluate if the user has configured CAN_CTRLMODE_FD or not?

Sorry, I was previously confused about our device's control mode. I
will use can_set_static_ctrlmode() to set CAN_FD mode in the next
patch.

Does your device support CAN-CC only mode? Does your device support to
switch between CAN-CC only and CAN-FD mode?

Our device supports both CAN-CC and CAN-FD mode.

This doesn't answer my question:

Does your device support CAN-CC only mode?

It can dynamically switch between CAN-CC and CAN-FD mode when
trasmitting or receiving, depending on whether the nct6694_can_frame
passs the flag with NCT6694_CAN_FRAME_FLAG_FD.

Ok, but what about the receive path? Does the device support CAN-CC only
mode? Will it throw an error, if it receives a CAN-FD frame?

No, it can receive both CAN-CC and CAN-FD frames, if the hardware
receives a CAN-FD frame, the firmware will set the
NCT6694_CAN_FRAME_FLAG_FD flag.