[PATCH v2 1/9] i2c: prepare runtime PM support for I2C client devices

[Kevin Hilman]

On Thu, Sep 12, 2013 at 2:34 PM, Kevin Hilman <khilman at linaro.org> wrote:
> Mika Westerberg <mika.westerberg at linux.intel.com> writes:
>
>> From: Aaron Lu <aaron.lu at intel.com>
>>
>> This patch adds runtime PM support for the I2C bus in a similar way that
>> has been done for PCI bus already. This means that the I2C bus core
>> prepares runtime PM for a client device just before a driver is about to be
>> bound to it. Devices that are not bound to any driver are not prepared for
>> runtime PM.
>>
>> In order to take advantage of this runtime PM support, the client device
>> driver needs drop the device runtime PM reference count by calling
>> pm_runtime_put() in its ->probe() callback and possibly implement rest of
>> the runtime PM callbacks.
>>
>> If the driver doesn't support runtime PM (like most of the existing I2C
>> client drivers), the device in question is regarded as being runtime PM
>> active and powered on.
>
> But for existing drivers which already support runtime PM (at least 7 by
> a quick grep), they will be stuck runtime enabled and stop hitting
> low-power states after this patch.

Oops, nevermind.  I was mixing this up with runtime PM on the i2c
adapter but this is for the i2c client.

Sorry for the noise.

Kevin