Re: sl811h_suspend() and PM_EVENT_PRETHAW state handling

From: Alan Stern
Date: Tue Aug 06 2013 - 17:21:42 EST

On Tue, 6 Aug 2013, Shuah Khan wrote:

> With the dev_pm_ops model, drivers have to provide interfaces for each
> one of these states.

No, they don't. They can leave out interfaces if they want.

> In this case, there will be a conflict since
> pm_op() treats this state as freeze where as the driver wants to do
> treat it as a suspend/hibernate. In the case of legacy pm_ops, state is
> passed in as a parameter and driver could take special action if need
> be, based on the state, however in dev_pm_ops model, state is not passed
> in. Instead it is handled with state specific pm_ops interfaces.
> For example, if this driver were to be converted to dev_pm_ops, it would
> require a freeze interface which will call sl811h_bus_suspend(). Once
> that is done, PM_EVENT_PRETHAW will be mapped to freeze() ops and
> sl811h_bus_suspend() will be called instead of port_power(sl811, 0);
> What I am getting at is, there is no provision to handle the special
> case for PM_EVENT_PRETHAW like in the case of this driver when using
> dev_pm_ops.

Okay. So what?

Alan Stern

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at