Re: [PATCH v4 3/3] media: ov7670: Add the s_power operation
From: Sakari Ailus
Date: Mon Sep 18 2017 - 09:26:56 EST
On Mon, Sep 18, 2017 at 05:26:16PM +0800, Yang, Wenyou wrote:
> Hi Sakari,
> On 2017/9/18 15:35, Sakari Ailus wrote:
> > Hi Wenyou,
> > Thanks for the update.
> > The driver exposes controls that are accessible through the sub-device node
> > even if the device hasn't been powered on.
> > Many ISP and bridge drivers will also power the sensor down once the last
> > user of the user space device nodes disappears. You could keep the device
> > powered at all times or change the behaviour so that controls can be
> > accessed when the power is off.
> > The best option would be to convert the driver to use runtime PM.
> Yes, I agree with you.
> I also noticed there are a lot of things needed to improve except for it,
> such as the platform data via device tree.
> I would like do it in another patch set. I will continue to work on it.
Adding runtime PM support later on sound good to me.
> > An example of this can be found in drivers/media/i2c/ov13858.c .
> A good example, thank you for your providing.