[LinuxPPS] A question about the PPS device.

[clemens at dwf.com]

Just a question.
I have installed the ' *ifdef N_PPS ' code that has been mentioned
in a number of emails recently in the ONCORE driver, and have
it working.  

Given a day or two to think about things Ill add it to the code in the
NTP repository.

But I dont understand this at all.

Using ttyctrl, the current code in the ONCORE driver worked just fine,
in particular, the PPS device was opened O_RDWR.
When I installed the #ifdef N_PPS code, it failed, I looked at ttyctrl.c and
saw that Rudolfo opened the device O_RDONLY, and changed the ONCORE
open to O_RDONLY, and now it works.

Mumph.

So why does the open in the same process with the set of the line discipline
have to be READONLY while the one in a different process can be READWRITE?

And since we are both sending/receiving information to the PPSAPI device
(granted thru IOCTLs) shouldn't it be READWRITE?

If there is a good reason for this, then others need to warned that their open
of the PPSAPI device needs to be RDONLY.


-- 
                                        Reg.Clemens
                                        reg at dwf.com