Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752851AbbBWRBE (ORCPT ); Mon, 23 Feb 2015 12:01:04 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:44038 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752543AbbBWRBC (ORCPT ); Mon, 23 Feb 2015 12:01:02 -0500 Date: Mon, 23 Feb 2015 08:59:55 -0800 From: Guenter Roeck To: Lukasz Majewski Cc: Eduardo Valentin , Kamil Debski , Jean Delvare , Kukjin Kim , lm-sensors@lm-sensors.org, Linux PM list , "linux-samsung-soc@vger.kernel.org" , devicetree@vger.kernel.org, Lukasz Majewski , Kukjin Kim , linux-kernel@vger.kernel.org, Sjoerd Simons , Abhilash Kesavan , Abhilash Kesavan Subject: Re: [PATCH v4 7/8] hwmon: pwm-fan: Read PWM FAN configuration from device tree Message-ID: <20150223165955.GA9417@roeck-us.net> References: <1418897591-18332-1-git-send-email-l.majewski@samsung.com> <1424254056-5904-1-git-send-email-l.majewski@samsung.com> <1424254056-5904-8-git-send-email-l.majewski@samsung.com> <54E7D0B3.7040800@roeck-us.net> <20150223171336.2e09ce50@amdc2363> <20150223162305.GB2165@roeck-us.net> <20150223175122.2c0a4645@amdc2363> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150223175122.2c0a4645@amdc2363> User-Agent: Mutt/1.5.23 (2014-03-12) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020206.54EB5CCE.0066,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.001 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: C_4847, X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 12 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1769 Lines: 65 On Mon, Feb 23, 2015 at 05:51:22PM +0100, Lukasz Majewski wrote: > Hi Guenter, > > > On Mon, Feb 23, 2015 at 05:13:36PM +0100, Lukasz Majewski wrote: > > > Hi Guenter, > > > > > [ ... ] > > > > > > > > > > If devicetree is not configured, of_property_count_elems_of_size > > > > returns -ENOSYS, which is returned, causing the driver to fail > > > > loading. > > > > > > Has of_property_count_elems_of_size() returns -ENOSYS? > > > > > > Maybe something has changed, but in my linux-vanila (3.19-rc4) > > > at ./drivers/of/base.c it returns -EINVAL, -ENODATA or number of > > > elements. > > > > > > Have I missed something? > > > > > Hi Lukasz, > > > > Yes, you have. Check include/linux/of.h, line 484, in latest mainline. > > Ok. Now I got it. > > The above situation shouldn't happen if I put of_find_property() check > on the very beginning of this function (it returns NULL when DT support > is not compiled). > Correct. > The function would look as follows: > > int > pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx > *ctx) > { > struct device_node *np = dev->of_node; > int num, i, ret; > > if (!of_find_property(np, "cooling-levels", NULL)) > return 0; > > ret = of_property_count_u32_elems(np, "cooling-levels"); > if (ret <= 0) { > dev_err(dev, "Wrong data!\n"); > return ret; This should probably be something like return ret ? : -EINVAL; or ret == 0 is not an error, and you should not display an error message in that case. Thanks, Guenter -- 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/