From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Sat, 08 Aug 2015 13:26:23 +0200
Subject: [PATCH 2/2] net, thunder, bgx: Add support for ACPI binding.
In-Reply-To: <20150807104320.GQ1820@rric.localhost>
References: <1438907590-29649-1-git-send-email-ddaney.cavm@gmail.com>
 <55C467A0.4020601@linaro.org> <20150807104320.GQ1820@rric.localhost>
Message-ID: <2414262.jivbxTLuUW@wuerfel>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Friday 07 August 2015 12:43:20 Robert Richter wrote:
> 
> I would not pollute bgx_probe() with acpi and dt specifics, and instead
> keep bgx_init_phy(). The typical design pattern for this is:
> 
> static int bgx_init_phy(struct bgx *bgx)
> {
> #ifdef CONFIG_ACPI
>         if (!acpi_disabled)
>                 return bgx_init_acpi_phy(bgx);
> #endif
>         return bgx_init_of_phy(bgx);
> }
> 
> This adds acpi runtime detection (acpi=no), does not call dt code in
> case of acpi, and saves the #else for bgx_init_acpi_phy().
> 

What you should really do is to use the same function for both,
using the generic device properties API. If that is not possible,
explain in a comment why not.

Aside from that, if you do have to use compile-time conditionals,
use 'if (IS_ENABLED(CONFIG_ACPI) && !acpi_disabled)' instead of
#ifdef, for readability. The compiler will produce the same binary,
but also give helpful warnings about incorrect code that you don't
get with #ifdef.

	Arnd