Re: [PATCH v2 1/9] i2c: prepare runtime PM support for I2C clientdevices

From: Mark Brown
Date: Fri Sep 13 2013 - 06:02:15 EST


On Fri, Sep 13, 2013 at 09:14:20AM +0800, Aaron Lu wrote:
> On 09/13/2013 06:06 AM, Sylwester Nawrocki wrote:

> > So there is currently no way to avoid this behaviour, i.e. to have the
> > adapter
> > not activated before any of its client devices is probed, but only later on,
> > after explicit call to pm_runtime_get*(&client->dev) in the client driver ?

> The above pm_runtime_get_sync is used to make sure when the client I2C
> device is going to be probed, its host adapter device is turned on(or we
> will fail the probe). It doesn't affect the adapter's status before the
> probe of I2C client device.

The expecation is that if the adaptor needs to do anything to transfer
it'll do that when asked to transfer - that way it can sit in a low
power state when the bus is idle.

Attachment: signature.asc
Description: Digital signature