Re: [PATCH v6 0/8] ptp: IEEE 1588 hardware clock support
From: Christian Riesch
Date: Thu Sep 23 2010 - 17:34:21 EST
Alan Cox wrote:
It implies clock tuning in userspace for a potential sub microsecond
accurate clock. The clock accuracy will be limited by user space
latencies and noise. You wont be able to discipline the system clock
accurately.
Noise matters, latency doesn't.
Well put! That's why we need hardware support for PTP timestamping to
reduce the noise, but get along well with the clock servo that is
steering the PHC in user space.
Christian
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