[LinuxPPS] ntp 'bugs'

[Udo van den Heuvel]

Rodolfo Giometti wrote:
> On Sun, Jun 29, 2008 at 11:44:33AM +0200, Udo van den Heuvel wrote:
> 
>> Yes and no.
>> Your rationale is right, but the agreed patch, at this time, from the
>> bug at https://support.ntp.org/bugs/show_bug.cgi?id=610 is at
>> https://support.ntp.org/bugs/attachment.cgi?id=405.
>> There you see that there is *no* time_pps_create for the NMEA carrying
>> serial line because we expect PPS from the PPS devcie which is tried next.
>> Of course this can be changed!
> 
> I referred to this patch:
> 
>    http://ftp.enneenne.com/pub/misc/linuxpps/refclocks/nmea/nmea.patch

the ntp folks don't refer to that patch.
So if we want nmea refclock to work we better update the bugzilla for ntpd.

> Can you use this patch?

Not until I patch the kernel for the line discipline change, which I
held off until now, waiting for 2.6.26 (which also brings us STA_NANO).

The patch has some issues which were resolved in the patch at
https://support.ntp.org/bugs/show_bug.cgi?id=610.
The structure was an issue of concern, one excessive sprintf can be
omitted? (after the else) and what if an other implementation changes
line discipline (or similar) like you do?
That is why I retry the /dev/gps0 device; stuff might have changed
because of the first open.


That retry block can of course be omitted without much consequence
besides what I mentioned.