[PATCH 0/8] LinuxPPS: some minor fixes and improvements.

[Andrey Drobyshev <immortalguardian1@gmail.com>]

Hello folks,

We are using PPS subsystem with kernel consumer in our long-lasting
project. (To be precise, kernel consumer and most of PPS drivers was
included in vanilla kernel by one of our employee Alexander Gordeev).

During the last years we have fixed dozen of issues and made some
improvements we'd like to give away. I split the patchset into
two parts. Here are some common fixes I'd like to submit. After that
I'll post some improvements in filtration algorithms to increase time
synchronization precision using low quality PPS sources with high
jitter (e.g. x86 box with pps_gen_parport).

I would like this patchset to be merged into current devel.

[PATCH 1/8] hardpps: simple fixes replacing clumsy code with abs() macro. 
[PATCH 2/8] ntp/pps: ignore pps_valid decreasing if there is no pps signal. 
[PATCH 3/8] hardpps: fix some pps_jitter issues. 
[PATCH 4/8] LinuxPPS: kapi: Unlock before waking up events queue in pps_event(). 
[PATCH 5/8] LinuxPPS: pps_parport: Do not generate assert in case of lost signal.
[PATCH 6/8] LinuxPPS: pps_parport: Ignore interrupt invoked less than 0.5 sec after previous.
[PATCH 7/8] LinuxPPS: pps_gen_parport: Add polarity parameter for inverted signal.
[PATCH 8/8] LinuxPPS: pps_gen_parport: Add check for bad clocksource.