Re: [PATCH v2 0/4] media: add and use fwnode_graph_for_each_endpoint_scoped()

[Sakari Ailus]

Hi Laurent,

On Thu, Jun 25, 2026 at 01:20:42AM +0300, Laurent Pinchart wrote:
> On Wed, Jun 24, 2026 at 03:46:48PM -0500, Frank Li wrote:
> > On Wed, Jun 24, 2026 at 11:02:37PM +0300, Laurent Pinchart wrote:
> > > On Wed, Jun 24, 2026 at 02:35:14PM -0500, Frank Li wrote:
> > > > On Wed, Jun 24, 2026 at 10:19:35PM +0300, Laurent Pinchart wrote:
> > > > > On Wed, Jun 24, 2026 at 01:00:08PM -0400, Frank.Li@xxxxxxxxxxx wrote:
> > > > > > Add new helper macro fwnode_graph_for_each_endpoint_scoped() and use it
> > > > > > simplify media code.
> > > > > >
> > > > > > Typical example should qualcomm's driver (camss.c), the v4l2_mc.c and
> > > > > > rkisp1-dev.c only silience improvement.
> > > > > >
> > > > > > Anyways, *_for_each_*_scoped() already use widely and make code clean.
> > > > > >
> > > > > > Build test only.
> > > > > >
> > > > > > Sakari Ailus:
> > > > > > 	when I try to improve the patch
> > > > > > "Add common helper library for 1-to-1 subdev registration", I found need
> > > > > > camss.c pattern, so I create this small improvement firstly.
> > > > >
> > > > > Those are nice cleanups, thank you.
> > > > >
> > > > > After applying this series, the only left users of the
> > > > > fwnode_graph_for_each_endpoint() macro are in drivers/base/property.c.
> > > >
> > > > I already checked previously, two place use it.
> > > >
> > > > fwnode_graph_get_endpoint_count(), it will go though all endpoints, last
> > > > ep is NULL, which totally equial to scoped() version.
> > > >
> > > > another one fwnode_graph_get_endpoint_by_id(), which return ep, expect
> > > > caller to call put().
> > > >
> > > > if use scoped() version, need use no_free_ptr() at return, which make think
> > > > a little bit complex.
> > >
> > > It would introduce a tiny bit of extra complexity there, but the
> > > advantage (in my opinion) is that we'll be able to remove the less safe
> > > fwnode_graph_for_each_endpoint() macro.
> > >
> > > Now one may argue that the risk of
> > > fwnode_graph_for_each_endpoint_scoped() is returning the iterator
> > > without using no_free_ptr(). I wonder if that would be easier to catch
> > > in static analysis tools than the current pattern that leaks a reference
> > > when exiting the loop early.
> > 
> > It's not big deal, if everyone prefer drop fwnode_graph_for_each_endpoint(),
> > I can do it.
> 
> Let's see what others think. If people prefer keeping both versions,
> I'll be OK with that.

I'd prefer to keep both: it depends on the use case which one is better. 

-- 
Kind regards,

Sakari Ailus