From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754844Ab3LPROu (ORCPT ); Mon, 16 Dec 2013 12:14:50 -0500 Received: from avon.wwwdotorg.org ([70.85.31.133]:39032 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753536Ab3LPROs (ORCPT ); Mon, 16 Dec 2013 12:14:48 -0500 Message-ID: <52AF3503.3010302@wwwdotorg.org> Date: Mon, 16 Dec 2013 10:14:43 -0700 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Hiroshi Doyu , Stephen Warren CC: "thierry.reding@gmail.com" , "robherring2@gmail.com" , "joro@8bytes.org" , "grant.likely@linaro.org" , "will.deacon@arm.com" , "mark.rutland@arm.com" , "devicetree@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "linux-tegra@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "lorenzo.pieralisi@arm.com" , "galak@codeaurora.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCHv6+ 01/13] of: introduce of_property_for_earch_phandle_with_args() References: <20131211.153338.2186623380643957232.hdoyu@nvidia.com><20131212113417.BDCD0C40637@trevor.secretlab.ca><20131212.141404.684884000513445038.hdoyu@nvidia.com> <20131214.175115.1251935659998248370.hdoyu@nvidia.com> In-Reply-To: <20131214.175115.1251935659998248370.hdoyu@nvidia.com> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/14/2013 08:51 AM, Hiroshi Doyu wrote: > Hiroshi Doyu wrote @ Thu, 12 Dec 2013 14:14:04 +0200 (EET): > >>>> From 8f7c0404aa68f0e8dbe0babc240590f6528ecc1f Mon Sep 17 00:00:00 2001 >>>> From: Hiroshi Doyu >>>> Date: Fri, 15 Nov 2013 10:52:53 +0200 >>>> Subject: [PATCH] of: introduce of_property_for_each_phandle_with_args() >>>> >>>> Iterating over a property containing a list of phandles with arguments >>>> is a common operation for device drivers. This patch adds a new >>>> of_property_for_each_phandle_with_args() macro to make the iteration >>>> simpler. >>>> >>>> Signed-off-by: Hiroshi Doyu >>>> Cc: Rob Herring > .... >>>> --- >>>> drivers/of/base.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ >>>> include/linux/of.h | 32 ++++++++++++++++++++++++++++++++ >>>> 2 files changed, 78 insertions(+) >>>> >>>> diff --git a/drivers/of/base.c b/drivers/of/base.c >>>> index f807d0e..cd4ab05 100644 >>>> --- a/drivers/of/base.c >>>> +++ b/drivers/of/base.c >>>> @@ -1201,6 +1201,52 @@ void of_print_phandle_args(const char *msg, const struct of_phandle_args *args) >>>> printk("\n"); >>>> } >>>> >>>> +const __be32 *of_phandle_iter_next(const char *cells_name, int cell_count, >>>> + const __be32 *cur, const __be32 *end, >>>> + struct of_phandle_args *out_args) >>> >>> Having to pass in cells_name, cell_count, cur and end each time seems a >>> little odd. Can a state structure be used instead? >>> >>> struct of_phandle_iter_state { >>> const char *cells_name; >>> int cells_count; >>> const __be32 *cur; >>> const __be32 *end; >>> struct of_phandle_args out_args; >>> } >>> >>> Make the caller provide one of those and fill it in with the init >>> function. >> >> I rewrote this a few times and so now I have a few version of this >> implementations :-) The above proposal is similar to the version v6+++ >> mentioned in the above patch note: >> >>>> v6+++: >>>> Introduced a new struct "of_phandle_iter" to keep the state when >>>> iterating over the list. >> >> which is: >> >> [RFC][PATCHv6+++ 01/13] of: introduce of_property_for_earch_phandle_with_args() >> http://lists.linuxfoundation.org/pipermail/iommu/2013-November/007087.html >> >> Stephen seemed to prefer the version without state struct. I like the >> idea to not pass the same arguments repeatly. Instead, wrapping them >> in a struct with state may look better. >> >> So if Stephen agrees, I'll rewrite the version with state struct >> again. > > Stephen, let me know what you think. It's hard to follow there have been so many revisions. As long as the result is reasonable, I'll be OK with it. IIRC, I objected to using a state structure for values that weren't needed by both functions, but if both functions need the values, that's fine. I suppose even if they don't both need the values, putting them in a state structure is OK too if it means the patch gets finished!