> -----Original Message----- > From: Richard Cochran <richardcoch...@gmail.com> > Sent: Friday, February 5, 2021 9:58 PM > To: Hutchinson, Brian (US) <brian.hutchin...@l3harris.com> > Cc: linuxptp-users@lists.sourceforge.net > Subject: [EXTERNAL] Re: [Linuxptp-users] Is LinuxPTP and LinuxPPS mutually > exclusive? > > On Fri, Feb 05, 2021 at 02:45:07PM +0000, Brian.Hutchinson--- via Linuxptp- > users wrote: > > > ... which got me to thinking, could LinuxPPS be getting in the way of the > 1PPS we're trying to generate with our fec_ptp imx8mm driver? > > No, certainly not. > > > Wondering if CONFIG_PPS should be turned off in kernel if we are doing > 1PPS with imx8 fec_php driver or is it needed? > > The CONFIG_PPS is selected by PTP, and so you cannot turn it off. > > config PTP_1588_CLOCK > tristate "PTP clock support" > depends on NET && POSIX_TIMERS > select PPS > > The reason for this is that some PTP Hardware Clock drivers generate events > for the PPS sub-system. However these are "software" time stamps and are > totally unrelated to actual "hardware" output signals.
Good to know. > > I'm not familiar with the IMX's FEC hardware, but IIRC it actually does not > support proper periodic output signals at all. I could be wrong, though. Yeah, it is a funky timer arrangement that results in the jitter I believe everyone (including me) complains about. Regards, Brian CONFIDENTIALITY NOTICE: This email and any attachments are for the sole use of the intended recipient and may contain material that is proprietary, confidential, privileged or otherwise legally protected or restricted under applicable government laws. Any review, disclosure, distributing or other use without expressed permission of the sender is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies without reading, printing, or saving. _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
