Re: [PATCH v6 4/5] device property: Constify fwnode_handle_get()

From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
	Rob Herring <robh@kernel.org>,
	ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>, Daniel Scally <djrscally@gmail.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rob Herring <robh+dt@kernel.org>,
	Frank Rowand <frowand.list@gmail.com>,
	Len Brown <lenb@kernel.org>
Subject: Re: [PATCH v6 4/5] device property: Constify fwnode_handle_get()
Date: Thu, 14 Apr 2022 00:47:20 +0300	[thread overview]
Message-ID: <YldE6L7MbgS0NXQY@paasikivi.fi.intel.com> (raw)
In-Reply-To: <YlcVFRQ9wJIH+sjI@smile.fi.intel.com>

On Wed, Apr 13, 2022 at 09:23:17PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 13, 2022 at 09:19:28PM +0300, Andy Shevchenko wrote:
> > On Wed, Apr 13, 2022 at 08:10:22PM +0200, Rafael J. Wysocki wrote:
> > > On Fri, Apr 8, 2022 at 8:49 PM Andy Shevchenko
> > > <andriy.shevchenko@linux.intel.com> wrote:
> 
> ...
> 
> > > > -struct fwnode_handle *fwnode_handle_get(struct fwnode_handle *fwnode)
> > > > +struct fwnode_handle *fwnode_handle_get(const struct fwnode_handle *fwnode)
> > > >  {
> > 
> > > >         if (!fwnode_has_op(fwnode, get))
> > > >                 return fwnode;
> > 
> > ^^^^, so it needs a casting, but then we have to comment why is so.
> 
> Note, it means that the fwnode parameter either invalid or has no given option.
> It's not a problem to drop casting in the first case, but the second one should
> be justified and Sakari wants to be sure that the initial container is not
> const, which seems can't be achieved even with the original code.

I wonder if I'm missing something. The fwnode argument originally was not
const here.

-- 
Sakari Ailus