[linux-pm] [RFC][PATCH 1/3] PM: Introduce new top level suspend and hibernation callbacks (rev. 4)

[Rafael J. Wysocki]

On Thursday, 27 of March 2008, Benjamin Herrenschmidt wrote:
> 
> On Thu, 2008-03-27 at 02:23 +0100, Rafael J. Wysocki wrote:
> > On Thursday, 27 of March 2008, Benjamin Herrenschmidt wrote:
> > > 
> > > > > There is absolutely no point getting a second struct anymore.
> > > > 
> > > > I obviously disagree with that opinion, so please elaborate.
> > > 
> > > Well, what does it bring you ? Why can't it be one struct ? To save
> > > space in the data area ?
> > 
> > Mostly, but not only that.
> > 
> > There are users of 'struct pm_ops' that aren't even supposed to define the
> > _noirq callbacks (device types and device classes), so I thought it would be
> > better to introduce a separate _noirq struct after all.
> 
> Make sense... USB has no use of noirq for example.

Well, FWIW, we can also do something like this:

struct pm_ops {
	int (*prepare)(struct device *dev);
	void (*complete)(struct device *dev);
	int (*suspend)(struct device *dev);
	int (*resume)(struct device *dev);
	int (*freeze)(struct device *dev);
	int (*thaw)(struct device *dev);
	int (*poweroff)(struct device *dev);
	int (*restore)(struct device *dev);
};

struct pm_ext_ops {
	struct pm_ops base;
	int (*suspend_noirq)(struct device *dev);
	int (*resume_noirq)(struct device *dev);
	int (*freeze_noirq)(struct device *dev);
	int (*thaw_noirq)(struct device *dev);
	int (*poweroff_noirq)(struct device *dev);
	int (*restore_noirq)(struct device *dev);
};

and use 'struct pm_ext_ops' for the entities that may need to implement the
_noirq callbacks.  This way we'll avoid the duplication of "_noirq" in the code
pointed to by Alex and there will be one "pm" pointer per bus type, device
type, device class, etc.

Thoughts?

Thanks,
Rafael