From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753959AbaJTWBu (ORCPT ); Mon, 20 Oct 2014 18:01:50 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:61363 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752836AbaJTWBp (ORCPT ); Mon, 20 Oct 2014 18:01:45 -0400 From: "Rafael J. Wysocki" To: Arnd Bergmann Cc: Grant Likely , Linux Kernel Mailing List , Greg Kroah-Hartman , Mika Westerberg , ACPI Devel Maling List , Aaron Lu , devicetree@vger.kernel.org, Linus Walleij , Alexandre Courbot , Dmitry Torokhov , Bryan Wu , Darren Hart , Mark Rutland Subject: Re: [PATCH v5 09/12] Driver core: Unified interface for firmware node properties Date: Tue, 21 Oct 2014 00:22:09 +0200 Message-ID: <5981363.HuOrK2kMZG@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <3213594.3tCDm06Aee@wuerfel> References: <2660541.BycO7TFnA2@vostro.rjw.lan> <7821406.D7i8JfDpzX@vostro.rjw.lan> <3213594.3tCDm06Aee@wuerfel> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, October 20, 2014 04:19:57 PM Arnd Bergmann wrote: > On Monday 20 October 2014 01:46:00 Rafael J. Wysocki wrote: > > > > > Something like: > > > > > > #define define_fwnode_accessors(__type, __devprop_type) \ > > > int device_property_read_##__type(struct device *dev, \ > > > const char *propname, __type *val) \ > > > { \ > > > if (IS_ENABLED(CONFIG_OF) && dev->of_node) \ > > > return of_property_read_##__type(dev->of_node, propname, val); \ > > > return acpi_dev_prop_read(ACPI_COMPANION(dev), propname, \ > > > __devprop_type, val); \ > > > } \ > > > int fwnode_property_read_##__type(struct fwnode_handle *fwnode, \ > > > const char *propname, __type *val) \ > > > { \ > > > if (IS_ENABLED(CONFIG_OF) && is_of_node(fwnode)) \ > > > return of_property_read_##__type(of_node(fwnode), propname, val); \ > > > else if (IS_ENABLED(CONFIG_ACPI) && is_acpi_node(fwnode)) \ > > > return acpi_dev_prop_read(acpi_node(fwnode), propname, \ > > > __devprop_type, val); \ > > > return -ENXIO; \ > > > } > > > > > > define_fwnode_accessors(u8, DEV_PROP_U8); > > > define_fwnode_accessors(u16, DEV_PROP_U16); > > > define_fwnode_accessors(u32, DEV_PROP_U32); > > > define_fwnode_accessors(u64, DEV_PROP_U64); > > > > > > That significantly reduces the code size for these things. > > > > So I was considering to do that, but eventually decided not to, because (1) > > adding kerneldoc comments to such things looks odd and (2) (which IMO is > > more important) this breaks LXR (for example, the thing at lxr.free-electrons.com > > that some people, including me in particular, occasionally use to check how things > > are defined). And even if you used the old good grep to look for a definition of > > fwnode_property_read_u8, say, this wouldn't work exactly as expected I'm afraid. > > Agreed, I'd also prefer your proposed code over Grant's macros. > > > I would very much like to retain the headers at least for this reason, if that's > > not a big deal. > > > > What I can do, however, is to use macros for generating the bodies of those > > functions. > > Yes, just don't do any concatenation to generate the names of the called > functions, i.e. > > return fwnode_call(of_property_read_u32, acpi_dev_prop_read, DEV_PROP_U32, node, propname, val); > > is better than > > return fwnode_call(u32, DEV_PROP_U32, node, propname, val); > > because it's easier to understand the call chain. There is one concatenation like that in the code I have today, but it was already present in the $subject series, in the of_dev_prop_read_array macro in patch #2 (and it actually makes sense to me). Rafael