[ltp] Re: Generic battery interface

[Shem Multinymous]

On 7/29/06, Mark Underwood <basicmark@yahoo.com> wrote:
> > The lazy polling approach I described in my last post to Vojtech
> > ("block until there's  a new readout or N milliseconds have passed,
> > whichever is later") looks like a more general, accurate and efficient
> > interface.
>
> This sounds like a good idea. You could do a similar thing using sysfs by
> providing a entry in sysfs which tells userland when the next update is going
> to happen, the userland app can then decide to use this as it's next poll time
> or not.

The driver may not know when the next update will happen, e.g., if its
data source is event-based. Moreover, the driver may be able to
*decide* when the next update will happen (i.e., when to query
poll-based hardware) if the clients say what they need in advance. The
"lazy poll" / "reverse select" handles both of these.

  Shem