Re: [RFCv1 PATCH 0/8] Allocate events per-event-type, v4l2-ctrls cleanup

[Sakari Ailus <sakari.ailus@iki.fi>]

Hans Verkuil wrote:
> This patch series consists of two parts: the first four patches change the
> way events are allocated and what to do when the event queue is full.
>
> These first four patches are the most important ones to review. The big
> change is that event allocation now happens when subscribing an event.
> So you not only specify which event you want to subscribe to for a particular
> filehandle, but also how many events should be reserved for that event type.
> Currently the driver specifies the number of events to allocate, but later
> this can be something that the application might want to set manually.
>
> This ensures that for each event type you will never entirely miss all events
> of a particular type. Currently this is a real possibility.
>
> The other change is that instead of dropping the new event if there is no more
> space available, the oldest event is dropped. This ensures that you get at
> least the latest state. And optionally a merge function can be provided that
> merges information of two events into one. This allows the control event to
> require just one event: if a new event is raised, then the new and old one
> can be merged and all state is preserved. Only the intermediate steps are
> no longer available. This makes for very good behavior of events and is IMHO
> a requirement for using the control event in a real production environment.
>
> The second four patches reorganize the way extended controls are processed
> in the control framework. This is the first step towards allowing control
> changes from within interrupt handlers. The main purpose is to move as much
> code as possible out of the critical sections. This reduces the size of
> those sections, making it easier to eventually switch to spinlocks for
> certain kinds of controls.
>
> It's lots of internal churn, so it's probably not easy to review. There are
> no real functional changes, however.

I have no further comments. Thus,

Acked-by: Sakari Ailus <sakari.ailus@iki.fi>

-- 
Sakari Ailus
sakari.ailus@iki.fi