[PATCH 1/8] OMAP PM: create a PM layer plugin for per-device constraints

Tony Lindgren tony at atomide.com
Thu May 5 02:00:13 EDT 2011


* Kevin Hilman <khilman at ti.com> [110504 17:33]:
> Tony,
> 
> Tony Lindgren <tony at atomide.com> writes:
> 
> > * jean.pihet at newoldbits.com <jean.pihet at newoldbits.com> [110504 06:32]:
> >>
> >> +int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t)
> > ...
> >
> >> +int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
> > ...
> >
> >> +int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r)
> > ...
> >
> > You should implement this as a Linux generic framework, we don't
> > want to add more omap specific frameworks.
> 
> This series isn't adding any new OMAP-specific frameworks.  The OMAP PM
> layer is already in place, and has been there for awhile.  OMAP PM is a
> layer which can have "plugins" so we can experiment with ways of
> handling constraints without changing the driver interface, and this
> series is just implementing a new plugin.

But in this case the plugin is just stubs. The only function that does
something is omap_pm_get_dev_context_loss_count. And then patch 8 in
this series starts adding a new omap specific features for constraints.

So the problem is patches 1 & 8 in this series. The rest is just fine
as it's the necessary omap hardware specific implementation.

> Once we are happy with a constraint layer, and can prove it will work,
> the plan is to get rid of the (existing) OMAP-specific APIs and propose
> a generic interface.

Well I don't think we should start building new omap specific layer on
an omap specific framework.

Instead, the constraint layer should be made generic to start with, even
if it's just a minimal implementation initially.

Maybe it could be just a generic header file to start with?

Regards,

Tony



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