> I hope you are right - question is always in number of available options > and which one to select - and, most important, explain it to the end user :(
The end customer being ptp4linux? At least for Marvell switches, it is happy about everything except that the switch is a bit slow, so we need to modify some of the time outs in the configuration file. > For example: > phc_index is returned as part of .get_ts_info() = cpsw_get_ts_info(), > so which intf should return phc_index? It is not a 1:1 relationship. See: https://elixir.bootlin.com/linux/latest/source/drivers/net/dsa/mv88e6xxx/hwtstamp.c#L61 All interfaces return the same index. In fact, for a switch, having a PHC per port would be odd. That would mean you need to sync the PHCs in order to act as a boundary clock. Andrew