On 12/8/2022 1:20 PM, Geva, Erez wrote: > On Wed, 2022-12-07 at 06:59 -0800, Richard Cochran wrote: >> On Thu, Nov 17, 2022 at 02:15:23PM -0800, Jacob Keller wrote: >>> On 11/17/2022 1:34 PM, Geva, Erez wrote: >> >>>> The problem is the fallback works only on build. >>>> But if the build system is newer than the running system, the >>>> fallback >>>> will fail, as you will use the PTP_CLOCK_GETCAPS2 which does not >>>> exist >>>> on the running old system. >>>> >>> >>> Fair. We likely have the same problem with some of the other "2" >>> ioctls, >>> since they're handled in a similar way. I think we do the Right(TM) >>> thing >>> for the sysoff.c where we probe the kernel at run-time. This could >>> be done >>> here but is probably not really worth it considering that >>> PTP_CLOCK_GETCAPS >>> functions the same way as PTP_CLOCK_GETCAPS2 for all kernels I >>> checked... So >>> I guess this is somewhat less likely. >> >> Jacob, do you want to have phc_ctl fall back to PTP_CLOCK_GETCAPS at >> run time if PTP_CLOCK_GETCAPS2 fails? > > We can use run-time fallback. > But personalty, I do not think it worth it. > Using PTP_CLOCK_GETCAPS2 is only done for one new field in a debug > tool. > We can simply wait till PTP_CLOCK_GETCAPS become obsolete or we have a > new PTP_CLOCK_GETCAPS3 to handle. > >> >>> I'm not sure if our other PTP ioctls are checked properly like this >>> at run >>> time... >> >> Maybe, but only because of sloppiness. Better to support older >> kernels at run time, as this is more user friendly. >> >> Working on embedded systems over the years, I've have often been that >> user, and, believe me, it is super annoying when the latest greatest >> App isn't backwards compatible. > > My view too :-) > >> >> Thanks, >> Richard > > > Erez
Agreed. Since there's no difference to using PTP_CLOCK_GETCAPS2 at least currently, it makes sense to just keep using PTP_CLOCK_GETCAPS. _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
