Re: [Linuxptp-users] Can ptp4l be used without phc2sys?

[Irene K. <Ir...@sa...>]

I am using vendor kernel and a vendor-specific PTP driver (drivers/net/Ethernet/freescale/fec_ptp.c).  I see this driver in the mainline kernel as well.  What enables PPS output signal is the PTP_ENABLE_PPS ioctl sent from linuxptp stack (in phc2sys.c).

-----Original Message-----
From: Richard Cochran [mailto:ric...@gm...] 
Sent: Tuesday, August 18, 2020 3:27 PM
To: Irene Kravets <Ir...@sa...>
Cc: lin...@li...
Subject: Re: [Linuxptp-users] Can ptp4l be used without phc2sys?

On Tue, Aug 18, 2020 at 12:34:55PM +0000, Irene Kravets wrote:
> I'd still like to understand why I get synchronized 1PPS signals (with 
> 2 usec delay) when I run both ptp4l and phc2sys, but if I only run 
> ptp4l, the 1PPS signals are not synchronized?  To clarify, with only 
> ptp4l running, the 1PPS signals from master and slave don't drift 
> relative to each other, but the delay between the signals is totally 
> random on each boot.  However, if I run ptp4l and phc2sync, the delay 
> is always between 2 and 3 usec.  Any ideas on why this is happening?

I wouldn't expect a PPS output signal in either case.  Normally you would have to enable the PPS output explicitly.

Probably you are using a vendor kernel with the vendor's hacks?

Or are you using an unaltered mainline Linux kernel?

Thanks,
Richard