Date: Mon, 18 Sep 2017 13:50:16 +0300
From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: john.hubbard@gmail.com
Cc: LKML <linux-kernel@vger.kernel.org>, Rob Herring <robh@kernel.org>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        John Hubbard <jhubbard@nvidia.com>
Subject: Re: [PATCH 1/1] acpi: unbreak ACPI_HANDLE(), encapsulate
 fwnode_operations
Message-ID: <20170918105016.lidyy6virab5cavy@paasikivi.fi.intel.com>
References: <20170916003527.3081-1-jhubbard@nvidia.com>
 <20170916003527.3081-2-jhubbard@nvidia.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20170916003527.3081-2-jhubbard@nvidia.com>
User-Agent: NeoMutt/20170113 (1.7.2)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1692
Lines: 45

Hi John,

On Fri, Sep 15, 2017 at 05:35:27PM -0700, john.hubbard@gmail.com wrote:
> From: John Hubbard <jhubbard@nvidia.com>
> 
> Due to commit db3e50f3234b ("device property: Get rid of struct
> fwnode_handle type field"), ACPI_HANDLE() inadvertently became
> a GPL-only call. The call path that led to that was:
> 
> ACPI_HANDLE()
>     ACPI_COMPANION()
>         to_acpi_device_node()
>             is_acpi_device_node()
>                 acpi_device_fwnode_ops
>                     DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops);
> 
> ...and the new DECLARE_ACPI_FWNODE_OPS() includes
> EXPORT_SYMBOL_GPL, whereas previously it was a static struct.
> 
> In order to avoid changing any of that, let's instead provide ever
> so slightly better encapsulation of those struct fwnode_operations
> instances. Those do not really need to be directly used in
> inline function calls in header files. Simply moving two small
> functions (is_acpi_device_node and is_acpi_data_node) out of
> acpi_bus.h, and into a .c file, does that.
> 
> That leaves the internals of struct fwnode_operations as GPL-only
> (which I think was the intent all along), but un-breaks any driver
> code out there that relies on the ACPI subsystem's being (historically)
> an EXPORT_SYMBOL-usable system. By that, I mean, ACPI_HANDLE() and
> other basic ACPI calls were non-GPL-protected.

Works for me.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

OF appears to have the same effective change; Rob: let me know if you'd
like me to send a patch for that, or whether this is preferred. On OF both
appear to be used (EXPORT_SYMBOL / EXPORT_SYMBOL_GPL).

-- 
Regards,

Sakari Ailus
sakari.ailus@linux.intel.com