From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B100CC433E0 for ; Tue, 2 Jun 2020 23:33:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 954B52067B for ; Tue, 2 Jun 2020 23:33:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728402AbgFBXdK (ORCPT ); Tue, 2 Jun 2020 19:33:10 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:57792 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727826AbgFBXdJ (ORCPT ); Tue, 2 Jun 2020 19:33:09 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id E7F788030835; Tue, 2 Jun 2020 23:33:06 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id A6Eb2LHBhb4B; Wed, 3 Jun 2020 02:33:06 +0300 (MSK) Date: Wed, 3 Jun 2020 02:33:05 +0300 From: Serge Semin To: Guenter Roeck CC: Serge Semin , Jean Delvare , kbuild test robot , Maxim Kaurkin , Alexey Malahov , , Subject: Re: [PATCH] hwmon: bt1-pvt: Declare Temp- and Volt-to-N poly when alarms are enabled Message-ID: <20200602233305.bprka2qx6e2tpfz5@mobilestation> References: <20200602091219.24404-1-Sergey.Semin@baikalelectronics.ru> <20200602140746.GA82514@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20200602140746.GA82514@roeck-us.net> X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 02, 2020 at 07:07:46AM -0700, Guenter Roeck wrote: > On Tue, Jun 02, 2020 at 12:12:19PM +0300, Serge Semin wrote: > > Clang-based kernel building with W=1 warns that some static const > > variables are unused: > > > > drivers/hwmon/bt1-pvt.c:67:30: warning: unused variable 'poly_temp_to_N' [-Wunused-const-variable] > > static const struct pvt_poly poly_temp_to_N = { > > ^ > > drivers/hwmon/bt1-pvt.c:99:30: warning: unused variable 'poly_volt_to_N' [-Wunused-const-variable] > > static const struct pvt_poly poly_volt_to_N = { > > ^ > > > > Indeed these polynomials are utilized only when the PVT sensor alarms are > > enabled. In that case they are used to convert the temperature and > > voltage alarm limits from normal quantities (Volts and degree Celsius) to > > the sensor data representation N = [0, 1023]. Otherwise when alarms are > > disabled the driver only does the detected data conversion to the human > > readable form and doesn't need that polynomials defined. So let's declare > > the Temp-to-N and Volt-to-N polynomials only if the PVT alarms are > > switched on at compile-time. > > > > Note gcc with W=1 doesn't notice the problem. > > > > Fixes: 87976ce2825d ("hwmon: Add Baikal-T1 PVT sensor driver") > > Reported-by: kbuild test robot > > Signed-off-by: Serge Semin > > Cc: Maxim Kaurkin > > Cc: Alexey Malahov > > I don't really like the added #if. Can you use __maybe_unused instead ? Ok. __maybe_unused is much better. Thanks for suggestion. -Sergey > > Thanks, > Guenter > > > --- > > drivers/hwmon/bt1-pvt.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/hwmon/bt1-pvt.c b/drivers/hwmon/bt1-pvt.c > > index 1a9772fb1f73..1a5212c04549 100644 > > --- a/drivers/hwmon/bt1-pvt.c > > +++ b/drivers/hwmon/bt1-pvt.c > > @@ -64,6 +64,7 @@ static const struct pvt_sensor_info pvt_info[] = { > > * 48380, > > * where T = [-48380, 147438] mC and N = [0, 1023]. > > */ > > +#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS) > > static const struct pvt_poly poly_temp_to_N = { > > .total_divider = 10000, > > .terms = { > > @@ -74,6 +75,7 @@ static const struct pvt_poly poly_temp_to_N = { > > {0, 1720400, 1, 1} > > } > > }; > > +#endif /* CONFIG_SENSORS_BT1_PVT_ALARMS */ > > > > static const struct pvt_poly poly_N_to_temp = { > > .total_divider = 1, > > @@ -96,6 +98,7 @@ static const struct pvt_poly poly_N_to_temp = { > > * N = (18658e-3*V - 11572) / 10, > > * V = N * 10^5 / 18658 + 11572 * 10^4 / 18658. > > */ > > +#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS) > > static const struct pvt_poly poly_volt_to_N = { > > .total_divider = 10, > > .terms = { > > @@ -103,6 +106,7 @@ static const struct pvt_poly poly_volt_to_N = { > > {0, -11572, 1, 1} > > } > > }; > > +#endif /* CONFIG_SENSORS_BT1_PVT_ALARMS */ > > > > static const struct pvt_poly poly_N_to_volt = { > > .total_divider = 10,