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

On Tue, Dec 28, 2021 at 06:03:39PM -0800, Richard Cochran wrote:

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

quoted

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.

Yes. That's what I mean.

quoted

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.

Thanks, I will pay attention on this when do user space implementation.

quoted

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 for this hint.

Cheers
Hangbin