[Intel-wired-lan] [PATCH v4 0/4] Patchset enabling hardware based cross-timestamps for next gen Intel platforms

Christopher S. Hall christopher.s.hall at intel.com
Mon Oct 12 18:45:18 UTC 2015


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



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