From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH] of: Turn of_match_node into a static inline when CONFIG_OF isn't set Date: Tue, 11 Feb 2014 20:17:59 +0100 Message-ID: <2194247.ngWdBSP92t@avalon> References: <1392122211-11422-1-git-send-email-laurent.pinchart@ideasonboard.com> <6446980.WMjvBYStRY@avalon> <20140211180845.GG841@joshc.qualcomm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20140211180845.GG841@joshc.qualcomm.com> Sender: linux-kernel-owner@vger.kernel.org To: Josh Cartwright Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Grant Likely , Rob Herring List-Id: devicetree@vger.kernel.org Hi Josh, On Tuesday 11 February 2014 12:08:46 Josh Cartwright wrote: > On Tue, Feb 11, 2014 at 06:20:49PM +0100, Laurent Pinchart wrote: > > On Tuesday 11 February 2014 10:48:26 Josh Cartwright wrote: > > > On Tue, Feb 11, 2014 at 03:55:35PM +0100, Laurent Pinchart wrote: > > > > On Tuesday 11 February 2014 08:41:08 Josh Cartwright wrote: > > > > > On Tue, Feb 11, 2014 at 01:36:51PM +0100, Laurent Pinchart wrote: > [..] > > > > I am a bit weary about having an of_match_node() user that both directly > > > dereferences the result (i.e. of_match_node(matches, np)->data) _and_ > > > builds when !CONFIG_OF; most likely due to a traumatic childhood event > > > where demons flew out my nose. > > > > I can assign the intermediate value to a variable before dereferencing it > > and drop my of_match_node() patch if it makes everybody happier. > > Assuming you also intend to handle the case of_match_node() may return > NULL, or otherwise prevent the execution of this codepath when > !CONFIG_OF, then, yes, that sounds good. I'll condition the call of that function to IS_ENABLED(CONFIG_OF), yes. > It sure would be convenient if platform_device had a 'const struct > of_device_id *of_id_entry' member similar to the existing struct > platform_device_id one, that was set up during platform device matching. > Most platform_driver users of of_match_node() would simply go away. There's definitely room for improvement (although in this particular case the driver handles an I2C device, not a platform device). I've always been slightly bothered by the duplication of matching information between native/legacy device IDs and OF device IDs. I haven't really given this a thought though, but I believe something should be done. I've just remembered that, in the I2C case, the I2C core selects the appropriate i2c_device_id matching entry based on the compatible string, provided that the i2c_device_id table matches the of_device_id table with I2C device names set to the OF compatible string with the vendor prefix stripped off. Just food for thought. -- Regards, Laurent Pinchart