Re: [PATCH 1/1] checkpatch: Deprecate V4L2 pipeline power management code

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Joe,

On Tue, Jul 14, 2026 at 05:11:17AM -0700, Joe Perches wrote:
> On Tue, 2026-07-14 at 14:14 +0300, Sakari Ailus wrote:
> > > Given this patch, checkpatch's message would be something like
> > > 
> > "Deprecated use of 'v4l2_pipeline_pm_get', prefer '' instead"
> > 
> > That's even technically correct: these functions serve no useful purpose
> > anymore, all new drivers effectively use Runtime PM anyway.
> 
> OK, but given that there are only 32 uses in 16 files in all
> of -next, why not just fix the uses then delete the functions?
> 
> $ git grep -P -w 'v4l2_pipeline_(?:link_notify|pm_get|pm_put)' | \
>   grep -vP '^(?:include|drivers/media/v4l2-core)' | \
>   wc -l
> 32
> 
> $ git grep -P -w -l 'v4l2_pipeline_(?:link_notify|pm_get|pm_put)' | \
>   grep -vP '^(?:include|drivers/media/v4l2-core)' | \
>   wc -l
> 16

There are about 20 V4L2 sub-device drivers that implement the s_power()
sub-device video callback used by the v4l2_pipeline_*() functions. These
are generally old drivers and the conversion is typically not entirely
trivial.

The intent here is to avoid adding new users to these functions now -- some
have slipped through recently.

> 
> > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > > []
> > > > @@ -879,6 +879,9 @@ our %deprecated_apis = (
> > > >  	"DEFINE_IDR"				=> "DEFINE_XARRAY",
> > > >  	"idr_init"				=> "xa_init",
> > > >  	"idr_init_base"				=> "xa_init_flags",
> > > > +	"v4l2_pipeline_link_notify"		=> "",
> > > > +	"v4l2_pipeline_pm_get"			=> "",
> > > > +	"v4l2_pipeline_pm_put"			=> "",
> > > 
> > > Add something like "v4l2 runtime power management API" instead
> > > At least point out what that is.
> > 
> > How about simply "Runtime PM"?
> 
> Better than nothing IMO.

I'll send v2 with that.

-- 
Regards,

Sakari Ailus