Re: [PATCH 1/5] Add functions producing system time given a backing counter value

On Mon, Jul 27, 2015 at 5:46 PM, Christopher Hall
[off-list ref] wrote:

* counter_to_rawmono64
* counter_to_mono64
* counter_to_realtime64

Enables drivers to translate a captured system clock counter to system
time. This is useful for network and audio devices that capture timestamps
in terms of both the system clock and device clock.

Huh.  So for counter_to_realtime64 & mono64, this seems to ignore the
fact that the multiplier is constantly adjusted and corrected. So that
calling the function twice with the same counter value may result in
different returned values.

I've not yet groked the whole patchset, but it seems like there needs
to be some mechanism that ensures the counter value is captured and
used in the same (or at least close) interval that the timekeeper data
is valid for.

thanks
-john