[email protected] wrote:
> On (03/21/09 14:58), Steven Stallion wrote:
>> Would it be possible to add in some verbiage about the persistence
>> lifecycle for driver developers?
> 
> I'm not seeing why driver developers would have to ever consider
> the persistence lifecycle for the IP interfaces (since these are IP 
> properties, not driver props). Can you clarify what you have in mind?

Provided a driver is written using the Phase I interfaces,
m_getprop/m_setprop may be called at any time (from an API perspective).
AFAIK most devices do not support dynamic reconfiguration - meaning that
most drivers tend to reset/reconfigure the device if m_setprop has been
called after the interface has been started.

I think its important to codify precisely when persisted properties are
set on a given interface. Provided these are set after the plumb, and
before m_start is called, this is fine. If these are done after the
interface has started, this could be a serious drag on performance for
those drivers which reset when a single property has been changed.

Perhaps now that persistence is in the picture, the Phase I interfaces
should be updated to support setting a batch of properties (m_setpropv?)
- this would reduce the number of device resets.

> However the answer to your next question describes the life-cycle
> 
>> Are persisted interface properties assigned post-plumb but pre-up?
> 
> yes, the properties will be applied after IP is plumbed, but before
> the interface is marked up.

This is good. Is it possible to document this specifically? MAC drivers
rely on the Brussels framework - detailing lifecycle is a good thing for
those of us who arent intimately familiar with the project.

>> Does the modification of properties and runtime stay the same as in Phase I?
> 
> There are some simplifications possible for global props
> because IP is never unloaded- (see Section 4). As for per-interface props,
> the current model only allows these to be modified when the interface
> is plumbed for IP (and will reapply the settings if the interface is
> unplumbed/plumbed). This constraint may be relaxed in the future, as we
> expand the design to allow more flexible configuration models.

This does not affect driver properties so my response likely has no
bearing, but...

It makes me a little nervous to rely on a given module always being
available (or unloadable). It is certainly foreseeable to see an
installation which does not make use of IP.

Regards,

Steve
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