igb: shorten maximum PHC timecounter update interval
The timecounter needs to be updated at least once per ~550 seconds in order to avoid a 40-bit SYSTIM timestamp to be misinterpreted as an old timestamp. Since commit 500462a9 ("timers: Switch to a non-cascading wheel"), scheduling of delayed work seems to be less accurate and a requested delay of 540 seconds may actually be longer than 550 seconds. Also, the PHC may be adjusted to run up to 6% faster than real time and the system clock up to 10% slower. Shorten the delay to 360 seconds to be sure the timecounter is updated in time. This fixes an issue with HW timestamps on 82580/I350/I354 being off by ~1100 seconds for few seconds every ~9 minutes. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:Miroslav Lichvar <mlichvar@redhat.com> Acked-by:
Jacob Keller <jacob.e.keller@intel.com> Acked-by:
Richard Cochran <richardcochran@gmail.com> Tested-by:
Aaron Brown <aaron.f.brown@intel.com> Signed-off-by:
Jeff Kirsher <jeffrey.t.kirsher@intel.com>
parent
d944b469
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