Re: [PATCHv3 net-next 1/2] net_tstamp: add new flag HWTSTAMP_FLAG_BONDED_PHC_INDEX

On Tue, Dec 28, 2021 at 08:17:48AM -0800, Jakub Kicinski wrote:

That's still just a compile-time fix,

I think Hangbin's immediate question was about compilation.  linuxptp
needs to be able to compile against older system headers.

if the user space binary 
is distributed in binary form (distro package) there is no knowing
on which kernel versions it will run. I think runtime probing will
be necessary.

Yes, that too.
 

If we want the define it should be to the enum name:

What about adding matching #defines into the enum declaration?

enum hwtstamp_flags {
	HWTSTAMP_FLAG_BONDED_PHC_INDEX = (1<<0),
#define HWTSTAMP_FLAG_BONDED_PHC_INDEX HWTSTAMP_FLAG_BONDED_PHC_INDEX
};

Examples in include/uapi/linux/rtnetlink.h

Ha!  I knew I saw this somewhere.

Thanks,
Richard