Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757811Ab2JSWn7 (ORCPT ); Fri, 19 Oct 2012 18:43:59 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:38275 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756997Ab2JSWn4 (ORCPT ); Fri, 19 Oct 2012 18:43:56 -0400 MIME-Version: 1.0 In-Reply-To: <5081D0B3.2060204@gmail.com> References: <507DF099.1010504@gmail.com> <5081D0B3.2060204@gmail.com> From: Grant Likely Date: Fri, 19 Oct 2012 23:43:35 +0100 X-Google-Sender-Auth: ik9JOMv84qPkpW0pKlR3V61bxw4 Message-ID: Subject: Re: [RFC PATCH] gpiolib: Refactor gpio_export To: Ryan Mallon Cc: Linus Walleij , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2027 Lines: 51 On Fri, Oct 19, 2012 at 11:14 PM, Ryan Mallon wrote: > On 19/10/12 21:07, Linus Walleij wrote: > >> On Wed, Oct 17, 2012 at 1:41 AM, Ryan Mallon wrote: >> >>> The gpio_export function uses nested if statements and the status >>> variable to handle the failure cases. This makes the function logic >>> difficult to follow. Refactor the code to abort immediately on failure >>> using goto. This makes the code slightly longer, but significantly >>> reduces the nesting and number of split lines and makes the code easier >>> to read. >>> >>> Signed-off-by: Ryan Mallon >> >> Very good initiative! >> >>> +++ b/drivers/gpio/gpiolib.c >>> @@ -702,68 +702,74 @@ int gpio_export(unsigned gpio, bool direction_may_change) >>> { >>> unsigned long flags; >>> struct gpio_desc *desc; >>> - int status = -EINVAL; >>> + int status; >>> const char *ioname = NULL; >>> + struct device *dev; >>> >>> /* can't export until sysfs is available ... */ >>> if (!gpio_class.p) { >>> pr_debug("%s: called too early!\n", __func__); >>> - return -ENOENT; >>> + status = -ENOENT; >>> + goto fail; >> >> Why bother with all the goto:s here since there are no resources >> to clean up? Just pr_debug() and return -ENOENT; is good enough. >> >> I don't quite see the point. > > I did it this way just so that there would be a single exit point. > I don't mind either way, so I'll update the ones without any > clean up to simply return. Single exit points are overrated. The code is shorter and easier to read to return immediately if there isn't any unwinding to do. g. -- 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/