From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v2 1/3] hwmon: (lm90) Add power control Date: Thu, 08 Aug 2013 12:45:28 -0600 Message-ID: <5203E748.2050601@wwwdotorg.org> References: <1375944991-29182-1-git-send-email-wni@nvidia.com> <1375944991-29182-2-git-send-email-wni@nvidia.com> <520359E9.1000600@roeck-us.net> <52036920.4050808@nvidia.com> <52037F9A.7070802@roeck-us.net> <5203D659.4050907@wwwdotorg.org> <20130808175918.GA15013@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130808175918.GA15013-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Guenter Roeck Cc: Wei Ni , "khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org" , Matthew Longnecker , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 08/08/2013 11:59 AM, Guenter Roeck wrote: > On Thu, Aug 08, 2013 at 11:33:13AM -0600, Stephen Warren wrote: >> On 08/08/2013 05:23 AM, Guenter Roeck wrote: >>> On 08/08/2013 02:47 AM, Wei Ni wrote: >> ... >>>> I think get_regulator() will return error values, not only >>>> -EPROBE_DEFER, so we should set data->lm90_reg to NULL to handle other >>>> error values. >>>> >>> Matter of opinion if you want to check for IS_ERR or NULL later on. >> >> No, if regulator returns either: >> >> * Something valid >> * Someting IS_ERR() >> >> ... then everywhere has to check the value using IS_ERR(). >> >> If regulator returns either: >> >> * Something valid >> * Someting NULL >> >> ... then everywhere has to check the value against NULL. >> > Other drivers calling get_regulator() don't check against NULL, > so it should not be needed here either. Right I should have mentioned that I believe regulator falls into the first valid-or-IS_ERR case, and not the second valid-or-NULL case.