Modern Intel hardware adds an Always Running Timer (ART) that allows the network and audio device clocks to precisely cross timestamp the device clock with the system clock. This allows a precise correlation of the device time and system time.
v4 adds a history which enables the audio DSP (a "slow" device) to perform cross-timestamping. Christopher S. Hall (4): Produce system time from correlated clocksource Always running timer correlated clocksource Add PTP_SYS_OFFSET_PRECISE for driver crosstimestamping Adds hardware supported cross timestamp Documentation/ptp/testptp.c | 6 +- arch/x86/include/asm/cpufeature.h | 2 +- arch/x86/include/asm/tsc.h | 2 + arch/x86/kernel/tsc.c | 48 ++++++- drivers/net/ethernet/intel/e1000e/defines.h | 5 + drivers/net/ethernet/intel/e1000e/ptp.c | 77 +++++++++++ drivers/net/ethernet/intel/e1000e/regs.h | 4 + drivers/ptp/ptp_chardev.c | 26 ++++ include/linux/clocksource.h | 33 +++++ include/linux/ptp_clock_kernel.h | 6 + include/linux/timekeeping.h | 4 + include/uapi/linux/ptp_clock.h | 12 +- kernel/time/timekeeping.c | 203 +++++++++++++++++++++++++++- 13 files changed, 418 insertions(+), 10 deletions(-) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
