HW timestamping e1000

[Konstantin Belousov]

On Tue, Jun 02, 2020 at 10:46:00AM +0000, Gabriel.Moyano at dlr.de wrote:
> Hi everybody,
> 
> Currently I am writing a piece of code to test HW timestamping on e1000 during reception, which runs on FreeBSD 12, but unfortunately it seems that it isn't working.
> 
> The socket is created and configured as follows:
> 
> sockfd = socket(AF_INET, SOCK_DGRAM, 0);
> int on = 1;
> setsockopt(sockfd, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on));
> 
> After recvmsg() is called, cmsg_type of received control messages are printed out with help of the control message routines (https://www.freebsd.org/cgi/man.cgi?query=CMSG_DATA). SCM_TIME_INFO should be printed out but it's not.
> 
> Is there any configuration missing? Does e1000 support HW timestamping right?
> 
> I will appreciate any help.

Hardware timestamping is only implemented for Mellanox ConnectX-4 and hier,
and Chelsio Terminators (T4 and newer ?).  It might be doable for Intel
some cards, but not all of them.