[LinuxPPS] multiple access to /dev/ppsN entries

[George Spelvin]

On Fri, Mar 19, 2010 at 07:33:33AM -0400, George Spelvin wrote:
>> Do you want the patches with the per-open offset?  Those are ready;
>> making the offset global got stalled and I have to pick it up again.

> Will they work correctly with kernel consumers? I imagine that's the
> only reason why they are part of the API. 

Ah, good point.  The current linuxpps patches don't have kernel consumers
(no time_pps_kcbind), so it's kind of academic, but it could easily
be handled by passing the offset to the ioctl that implements *that*.

The hairy bit comes up when you want to combine that with a later program
opening the PPS device and invoking pps_getparams().  Does it return
the kernel consumer offset, or its per-open offset?

If people would like to discuss a cleaner, less literal kernel
PPS interface, I'm very interested.