On Friday, December 17, 2010, Mark Brown wrote:
> On Fri, Dec 17, 2010 at 02:49:25PM +0100, Rafael J. Wysocki wrote:
> > On Friday, December 17, 2010, Mark Brown wrote:
>
> > > By, for example, providing default implementations which the buses can
> > > use if they choose to.
>
> > OK, so we have generic_subsys_pm_ops. Do we need anything beyond that?
>
> Hrm. Possibly just some fiddling with those or alternative versions.
> For example, looking at the I2C bus suspend it's this:
>
> static int i2c_device_pm_suspend(struct device *dev)
> {
> const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
>
> if (pm) {
> if (pm_runtime_suspended(dev))
> return 0;
> else
> return pm->suspend ? pm->suspend(dev) : 0;
> }
>
> return i2c_legacy_suspend(dev, PMSG_SUSPEND);
> }
>
> Ideally the if (pm) block could just be factored out into the pm core as
> there's nothing I2C-specific about that at all. Possibly even the whole
> logic surrounding fall back to legacy, though that smells a bit.
No, the legacy is i2c-specific.
> The generic suspend operation doesn't fit here:
>
> int pm_generic_suspend(struct device *dev)
> {
> return __pm_generic_call(dev, PM_EVENT_SUSPEND);
> }
> EXPORT_SYMBOL_GPL(pm_generic_suspend);
Well, looking at __pm_generic_call(), I think it does.
It appears to do exactly what the pm block above does, so it should be possible
to have something like this:
static int i2c_device_pm_suspend(struct device *dev)
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
return pm ? pm_generic_suspend(dev) : i2c_legacy_suspend(dev, PMSG_SUSPEND);
}
if I'm not missing anything.
Thanks,
Rafael
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