For the record, I adjusted some kernel configurations and the offsets are now down to the ~20-30 ns range on the i350 card.
The differences are adjustments to PCI bus performance modes. Aris Previous kernel (5.19.0-2-rt-amd64) - had large swings in offsets: < CONFIG_CC_VERSION_TEXT="gcc-11 (Debian 11.3.0-6) 11.3.0" < CONFIG_GCC_VERSION=110300 < CONFIG_AS_VERSION=23890 < CONFIG_LD_VERSION=23890 < CONFIG_PCIEASPM_DEFAULT=y < # CONFIG_PCIEASPM_PERFORMANCE is not set < CONFIG_PCIE_BUS_DEFAULT=y < # CONFIG_PCIE_BUS_PERFORMANCE is not set < CONFIG_PPS=m < CONFIG_PTP_1588_CLOCK=m < CONFIG_PTP_1588_CLOCK_OPTIONAL=m New kernel (5.19.11-rt9-amd64) - now offsets are behaving as expected (generally low 20-30ns offsets observed across all i350 ports): > CONFIG_CC_VERSION_TEXT="gcc (Debian 12.2.0-3) 12.2.0" > CONFIG_GCC_VERSION=120200 > CONFIG_AS_VERSION=23900 > CONFIG_LD_VERSION=23900 > CONFIG_BUILD_SALT="" > CONFIG_CC_NO_ARRAY_BOUNDS=y > CONFIG_MODULE_SIG_ALL=y > # CONFIG_PCIEASPM_DEFAULT is not set > CONFIG_PCIEASPM_PERFORMANCE=y > # CONFIG_PCIE_BUS_DEFAULT is not set > CONFIG_PCIE_BUS_PERFORMANCE=y > CONFIG_PPS=y > CONFIG_PTP_1588_CLOCK=y > CONFIG_PTP_1588_CLOCK_OPTIONAL=y > CONFIG_CC_HAS_AUTO_VAR_INIT_PATTERN=y > CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO=y _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
