On Thu, Oct 06, 2022 at 12:11:39AM +0200, Janusz Użycki wrote: > Hi. > > A lot of PTP/PHC drivers set max_adj value quite big. Howover due to > kernel's API limit of 32bit long type value (freq) and POSIX frequency > conversion it should limited to 32767999 ppb. > > It concerns the frequency limit check both for kernel, testptp and ptp4linux > servos. Simply 65.536 * 32767999 is almost 2^31... It is also common for > adjfreq() vs newer adjfine(). > Moreover such big frequency limits seem not practical (phase jump used > instead, 1000ppm is huge for any PTP oscillator application), even driver or > rather PHC hardware has ability to tune is such range.
What issue are you seeing with linuxptp? In phc_max_adj() there is some code clamping the value on 32-bit systems, so the overflow should be avoided. -- Miroslav Lichvar _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
