Dear Miro, > Yes, it's related to PCIe delays. The problem is that the kernel > doesn't provide an ioctl to measure offset between two PHCs, so > phc2sys has to do it in user space using clock_gettime(), which > doesn't work very well (large delay, jitter and asymmetry).
Yes it seems like the clock_gettime() api is not very accurate, the delay introduced by the switchover between userspace and kernel space may vary a lot. But it's confusing me that when I run several independent phc2sys instances at the same time, every one just looks fine, the offset value varies in the range of two-digit nanoseconds. Let me do more tests to locate the problem. Regards, Yuezhen Luan _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
