From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751863AbaK3AMQ (ORCPT ); Sat, 29 Nov 2014 19:12:16 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:37027 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751794AbaK3AMP (ORCPT ); Sat, 29 Nov 2014 19:12:15 -0500 Date: Sat, 29 Nov 2014 16:12:07 -0800 From: Guenter Roeck To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Arnd Bergmann , Greg Kroah-Hartman , Steven Honeyman , linux-kernel@vger.kernel.org Subject: Re: [PATCH] i8k: Fix temperature bug handling in i8k_get_temp() Message-ID: <20141130001207.GA26101@roeck-us.net> References: <201411181546.51284@pali> <1416322614-10308-1-git-send-email-pali.rohar@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1416322614-10308-1-git-send-email-pali.rohar@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) 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=0001.0A020202.547A60DF.003D,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: 5 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 On Tue, Nov 18, 2014 at 03:56:54PM +0100, Pali Rohár wrote: > Static array prev[] was incorrectly initialized. It should be initialized to > some "invalid" temperature value (above I8K_MAX_TEMP). > > Next, function should store "invalid" value to prev[] (above I8K_MAX_TEMP), > not valid (= I8K_MAX_TEMP) because whole temperature bug handling will not > work. > > And last part, to not break existing detection of temperature sensors, register > them also if i8k report too high temperature (above I8K_MAX_TEMP). This is > needed because some sensors are sometimes turned off (e.g sensor on GPU which > can be turned off/on) and in this case SMM report too high value. > > To prevent reporting "invalid" values to userspace, return -EINVAL. In this case > sensors which are currently turned off (e.g optimus/powerexpress/enduro gpu) > are reported as "N/A" by lm-sensors package. > > Signed-off-by: Pali Rohár > --- > drivers/char/i8k.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c > index 7272b08..e34a019 100644 > --- a/drivers/char/i8k.c > +++ b/drivers/char/i8k.c > @@ -298,7 +298,7 @@ static int i8k_get_temp(int sensor) > int temp; > > #ifdef I8K_TEMPERATURE_BUG > - static int prev[4]; > + static int prev[4] = { I8K_MAX_TEMP+1, I8K_MAX_TEMP+1, I8K_MAX_TEMP+1, I8K_MAX_TEMP+1 }; This results in a checkpatch warning. Please split, and add a space before and after '+'. Actually, I would suggest to use something something like #define I8K_INVALID_TEMP (I8K_MAX_TEMP + 1) and to use it instead of hard-coding "I8K_MAX_TEMP + 1" in the code. > #endif > regs.ebx = sensor & 0xff; > rc = i8k_smm(®s); > @@ -317,10 +317,12 @@ static int i8k_get_temp(int sensor) > */ > if (temp > I8K_MAX_TEMP) { > temp = prev[sensor]; > - prev[sensor] = I8K_MAX_TEMP; > + prev[sensor] = I8K_MAX_TEMP+1; > } else { > prev[sensor] = temp; > } > + if (temp > I8K_MAX_TEMP) > + return -ERANGE; > #endif > > return temp; > @@ -499,6 +501,8 @@ static ssize_t i8k_hwmon_show_temp(struct device *dev, > int temp; > > temp = i8k_get_temp(index); > + if (temp == -ERANGE) > + return -EINVAL; > if (temp < 0) > return temp; > return sprintf(buf, "%d\n", temp * 1000); > @@ -610,17 +614,17 @@ static int __init i8k_init_hwmon(void) > > /* CPU temperature attributes, if temperature reading is OK */ > err = i8k_get_temp(0); > - if (err >= 0) > + if (err >= 0 || err == -ERANGE) > i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1; > /* check for additional temperature sensors */ > err = i8k_get_temp(1); > - if (err >= 0) > + if (err >= 0 || err == -ERANGE) > i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2; > err = i8k_get_temp(2); > - if (err >= 0) > + if (err >= 0 || err == -ERANGE) > i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3; > err = i8k_get_temp(3); > - if (err >= 0) > + if (err >= 0 || err == -ERANGE) > i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4; > > /* Left fan attributes, if left fan is present */ > -- > 1.7.9.5 >