Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753248AbaAZXO5 (ORCPT ); Sun, 26 Jan 2014 18:14:57 -0500 Received: from mail-pa0-f44.google.com ([209.85.220.44]:59932 "EHLO mail-pa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753144AbaAZXOz (ORCPT ); Sun, 26 Jan 2014 18:14:55 -0500 Date: Sun, 26 Jan 2014 15:14:52 -0800 From: Dmitry Torokhov To: Dmitry Eremin-Solenikov Cc: Tomasz Figa , Manish Badarkhe , "linux-samsung-soc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , David Woodhouse Subject: Re: [PATCH] max8925_power: Use "IS_ENABLED(CONFIG_OF)" for DT code. Message-ID: <20140126231452.GE18840@core.coreip.homeip.net> References: <1390720540-13350-1-git-send-email-badarkhe.manish@gmail.com> <52E50C24.8030305@gmail.com> <20140126214542.GC18840@core.coreip.homeip.net> <52E582D0.9070501@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 27, 2014 at 02:31:59AM +0400, Dmitry Eremin-Solenikov wrote: > On Mon, Jan 27, 2014 at 1:49 AM, Tomasz Figa wrote: > > On 26.01.2014 22:45, Dmitry Torokhov wrote: > >> > >> On Sun, Jan 26, 2014 at 07:31:50PM +0530, Manish Badarkhe wrote: > >>> > >>> Hi Tomasz, > >>> > >>> Thank you for your review comments. > >>> > >>> On Sun, Jan 26, 2014 at 6:52 PM, Tomasz Figa > >>> wrote: > >>>> > >>>> > >>>> Hi Manish, > >>>> > >>>> > >>>> On 26.01.2014 08:15, Manish Badarkhe wrote: > >>>>> > >>>>> > >>>>> Instead of "#if define CONFIG_OF" use "IS_ENABLED(CONFIG_OF)" > >>>>> option for DT code to avoid if-deffery in code. > >>>>> > >>>>> Signed-off-by: Manish Badarkhe > >>>>> --- > >>>>> :100644 100644 b4513f2... d353fbc... M drivers/power/max8925_power.c > >>>>> drivers/power/max8925_power.c | 14 +++++--------- > >>>>> 1 file changed, 5 insertions(+), 9 deletions(-) > >>>>> > >>>>> diff --git a/drivers/power/max8925_power.c > >>>>> b/drivers/power/max8925_power.c > >>>>> index b4513f2..d353fbc 100644 > >>>>> --- a/drivers/power/max8925_power.c > >>>>> +++ b/drivers/power/max8925_power.c > >>>>> @@ -427,7 +427,6 @@ static int max8925_deinit_charger(struct > >>>>> max8925_power_info *info) > >>>>> return 0; > >>>>> } > >>>>> > >>>>> -#ifdef CONFIG_OF > >>>>> static struct max8925_power_pdata * > >>>>> max8925_power_dt_init(struct platform_device *pdev) > >>>>> { > >>>>> @@ -468,13 +467,6 @@ max8925_power_dt_init(struct platform_device > >>>>> *pdev) > >>>>> > >>>>> return pdata; > >>>>> } > >>>>> -#else > >>>>> -static struct max8925_power_pdata * > >>>>> -max8925_power_dt_init(struct platform_device *pdev) > >>>>> -{ > >>>>> - return pdev->dev.platform_data; > >>>>> -} > >>>>> -#endif > >>>>> > >>>>> static int max8925_power_probe(struct platform_device *pdev) > >>>>> { > >>>>> @@ -483,7 +475,11 @@ static int max8925_power_probe(struct > >>>>> platform_device *pdev) > >>>>> struct max8925_power_info *info; > >>>>> int ret; > >>>>> > >>>>> - pdata = max8925_power_dt_init(pdev); > >>>>> + if (IS_ENABLED(CONFIG_OF)) > >>>>> + pdata = max8925_power_dt_init(pdev); > >>>>> + else > >>>>> + pdata = pdev->dev.platform_data; > >>>>> + > >>>> > >>>> > >>>> > >>>> This does not look much better than before this patch. Instead of > >>>> "if-deffery" outside function bodies you are adding "iffery" (if there is > >>>> such a word) inside a function. > >>>> What about adding > >>>> > >>>> if (!IS_ENABLED(CONFIG_OF)) > >>>> return pdev->dev.platform_data; > >>>> > >>>> on top of max8925_power_dt_init() instead or maybe also renaming this > >>>> function to max8925_get_pdata()? > >>> > >>> > >>> Okay, I will rename function "max8925_power_dt_init()" to > >>> "max8925_get_pdata()". > >>> As you suggested, in the body of this function will add a logic to > >>> retrieve data in case > >>> of DT and non-DT platforms. > >> > >> > >> Should we not always favor platform-supplied data regardless of > >> CONFIG_OF state and fall back to DT (firmware) supplied data if platform > >> data is absent? This way one can tweak kernel behavior without needing > >> to change firmware. > > > > > > I guess we should, but apparently this was not the original behavior before > > this patch, so I'm not sure if we should be squashing such semantic change > > with this simple refactor. > > Hmm. Judging from the code, max8925_power_dt_init() function follows exactly > opposite strategy - it uses platform_data if of_node is not populated/available. > So (if dt_init will compile with CONFIG_OF disabled) one can always > use _dt_init() > function to retrieve pdata. Right, and I question whether this is good behavior or if it should be corrected. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/