Re: [PATCH v2 37/66] media: sun6i-csi: Move power management to runtime pm in capture

Laurent Pinchart
2022-02-15T10:05:53Z

Hi Paul,

On Tue, Feb 15, 2022 at 10:56:22AM +0100, Paul Kocialkowski wrote:
> On Mon 14 Feb 22, 20:30, Sakari Ailus wrote:
> > On Sat, Feb 05, 2022 at 07:54:00PM +0100, Paul Kocialkowski wrote:
> > > Let's just enable the module when we start using it (at stream on)
> > > and benefit from runtime pm instead of enabling it at first open.
> > >
> > > Also reorder the call to v4l2_pipeline_pm_get.
> > >
> > > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> >
> > Nice patch!
>
> Thanks!
>
> > Do you still need v4l2_pipeline_pm_put()? Removing it would be a separate
> > patch of course.
>
> My understanding is that this is still useful if there are drivers in the
> pipeline that rely on s_power instead of rpm (a typical case could be an
> old sensor driver). So that's why this is kept around, but all other components
> of the pipeline (isp/csi/mipi csi-2) are using rpm now.

If that's not the case on your test platforms, I think it would be
better to drop support for this old API, and convert drivers that still
use .s_power() if someone needs to use one on an Allwinner platform.

--
Regards,

Laurent Pinchart