On Tuesday, September 17, 2013 12:31:11 AM Mark Brown wrote: > On Mon, Sep 16, 2013 at 09:07:07PM +0200, Rafael J. Wysocki wrote: > > > That may be left to the client driver altogether. I mean, if the client > > wants > > the controller to be powered up, it should just call > > pm_runtime_get_sync(controller device) at a suitable place (and then do the > > corresponding _put when the controller is not necessary anu more) from its > > ->probe() callback. > > It shouldn't even need to do that, it should just be able to rely on the > controller to power itself up when asked to do work. This is how the > existing implementations are done - the controller power management is > totally transparent to the slave.
If both the I2C client and I2C controller have corresponding objects in the ACPI namespace and the client's object is a child of the controller's object, then in order to power up the client we need to power up the controller even if no transactions are going to be carried out. That's what the spec simply requires us to do in that case. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
