Re: ntpd stratum 1 funny offset with NetBSD 6 branch

[christos%astron.com@localhost (Christos Zoulas)]

In article <20130719161217.0E1135989B%thoreau.thistledown.com.au@localhost>,
Simon Burge  <simonb%NetBSD.org@localhost> wrote:
>Hi Frank!
>
>Frank Kardel wrote:
>
>> Hi Simon  !
>> 
>> Two observations:
>> NetBSD 5 has 4.2.4p6.
>> 
>> NetBSD 6+current have 4.2.6p5.
>
>I did try 4.2.4p6 (from NetBSD 5) on NetBSD 6 and behaves the same
>broken way.
>
>Just for kicks, I tried a NetBSD 6 kernel on NetBSD 5 but ntpd reports
>
>       refclock_nmea: time_pps_setparams failed: Inappropriate ioctl for device
>
>which I'm guessing is 64-bit time_t lossage as a timespec would be
>larger in NetBSD 6 and it doesn't appear that the PPS ioctls are
>versioned.

Yes, I missed versioning those. I guess it is too late to do it now :-)


>
>> Also note that the PPS samples seems to be ~two seconds apart and there is
>> also a difference of ~2 seconds between now and the asser time stamp.
>> The ATOM driver should be just using the difference between the fictive
>> integral second and the time stamp. So from the data given ATOM's behavior
>> looks strange here. Even more so as the other peers seem to indicate 
>> basically
>> good synchronization.
>> 
>> Further step:
>> Verify that PPS is picked up correctly:
>>      - go to /src/external/bsd/ntp/dist/util and make pps-api
>>      - call pps-api with your PPS device
>
>pps-api seems happy (after fixing the printf formats and adding a "now"
>timestamp):
>
>              now               assert                clear
>1374243213.014227 1374243213.000706506          0.000000000  1  0 -1374243213.
>1374243213.044193 1374243213.000706506 1374243213.040716223  1  1  0.040009717
>1374243214.004211 1374243214.000707691 1374243213.040716223  2  1 -0.959991468
>1374243214.044193 1374243214.000707691 1374243214.040709742  2  2  0.040002051
>1374243215.004256 1374243215.000719951 1374243214.040709742  3  2 -0.960010209
>1374243215.044235 1374243215.000719951 1374243215.040717408  3  3  0.039997457
>1374243216.004255 1374243216.000709099 1374243215.040717408  4  3 -0.959991691
>1374243216.044239 1374243216.000709099 1374243216.040711668  4  4  0.040002569
>1374243217.004302 1374243217.000710099 1374243216.040711668  5  4 -0.959998431
>1374243217.044281 1374243217.000710099 1374243217.040712297  5  5  0.040002198
>1374243218.004283 1374243218.000711247 1374243217.040712297  6  5 -0.959998950
>1374243218.044265 1374243218.000711247 1374243218.040713038  6  6  0.040001791
>1374243219.004329 1374243219.000716543 1374243218.040713038  7  6 -0.960003505
>1374243219.044300 1374243219.000716543 1374243219.040726372  7  7  0.040009829
>1374243220.004297 1374243220.000712877 1374243219.040726372  8  7 -0.959986505
>1374243220.044281 1374243220.000712877 1374243220.040714927  8  8  0.040002050
>1374243221.004344 1374243221.000710507 1374243220.040714927  9  8 -0.959995580
>1374243221.044324 1374243221.000710507 1374243221.040727594  9  9  0.040017087
>1374243222.004321 1374243222.000714544 1374243221.040727594 10  9 -0.959986950
>1374243222.044303 1374243222.000714544 1374243222.040716742 10 10  0.040002198
>
>Both the PPS assert and clear timestamps look very regular, and also are
>appearing every second (not every second second as was seemingly being
>reported by ntpd).  I think (hope!) this is telling me that the hardware
>CD interrupt stuff is working fine.
>
>However, I do only see NMEA sentences every second second:
>
>$GPRMC,160808,A,3810.2933,S,14418.4083,E,000.0,000.0,190713,011.5,E,A*0F
>$GPGGA,160808,3810.2933,S,14418.4083,E,1,07,1.0,78.0,M,-2.1,M,,*79
>$GPGSA,A,3,02,04,12,15,17,24,28,,,,,,2.3,1.0,2.0*3B
>$GPGSV,3,1,09,02,26,004,46,04,48,044,35,12,28,242,47,15,19,299,26*78
>$GPGSV,3,2,09,17,47,135,51,24,54,239,47,28,16,089,19,09,10,029,00*7C
>$GPGSV,3,3,09,26,09,339,00*44
>$PGRME,3.0,M,6.6,M,7.3,M*29
>$GPRMC,160810,A,3810.2933,S,14418.4083,E,000.0,000.0,190713,011.5,E,A*06
>$GPGGA,160810,3810.2933,S,14418.4083,E,1,07,1.0,78.0,M,-2.1,M,,*70
>$GPGSA,A,3,02,04,12,15,17,24,28,,,,,,2.3,1.0,2.0*3B
>$GPGSV,3,1,09,02,26,004,46,04,48,044,35,12,28,242,47,15,19,299,26*78
>$GPGSV,3,2,09,17,47,135,51,24,54,239,47,28,16,089,20,09,10,029,00*76
>$GPGSV,3,3,09,26,09,339,00*44
>$PGRME,3.0,M,6.5,M,7.2,M*2B
>$GPRMC,160812,A,3810.2933,S,14418.4083,E,000.0,000.0,190713,011.5,E,A*04
>$GPGGA,160812,3810.2933,S,14418.4083,E,1,07,1.0,78.0,M,-2.1,M,,*72
>$GPGSA,A,3,02,04,12,15,17,24,28,,,,,,2.3,1.0,2.0*3B
>$GPGSV,3,1,09,02,26,004,46,04,48,044,35,12,28,242,47,15,19,299,25*7B
>$GPGSV,3,2,09,17,47,135,51,24,54,239,47,28,16,089,22,09,10,029,00*74
>$GPGSV,3,3,09,26,09,339,00*44
>$PGRME,3.0,M,6.5,M,7.1,M*28
>
>Is that enough to confuse ntpd?

I don't know. I would not think so.

christos