Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754852AbaAHCDU (ORCPT ); Tue, 7 Jan 2014 21:03:20 -0500 Received: from mga09.intel.com ([134.134.136.24]:55873 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753627AbaAHCDN (ORCPT ); Tue, 7 Jan 2014 21:03:13 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,621,1384329600"; d="scan'208";a="435445742" Message-ID: <1389146573.6486.1.camel@rzhang1-mobl4> Subject: Re: [PATCH] hwmon/sensors: fix SENSORS_LM75 dependencies From: Zhang Rui To: Jean Delvare Cc: Eduardo Valentin , Guenter Roeck , Randy Dunlap , Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Frodo Looijaard , lm-sensors@lm-sensors.org, linux-pm@vger.kernel.org Date: Wed, 08 Jan 2014 10:02:53 +0800 In-Reply-To: <20140107152148.36768345@endymion.delvare> References: <20140106204020.b47e53cc3ead8f90164ef5b7@canb.auug.org.au> <52CB0948.6030702@infradead.org> <20140106203209.GA21630@roeck-us.net> <52CB53DC.4030901@infradead.org> <52CB65DA.2010103@roeck-us.net> <20140107130401.23bffcd2@endymion.delvare> <52CBF1CF.2000603@ti.com> <20140107152148.36768345@endymion.delvare> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2014-01-07 at 15:21 +0100, Jean Delvare wrote: > Hi Eduardo, > > On Tue, 7 Jan 2014 08:23:43 -0400, Eduardo Valentin wrote: > > On 07-01-2014 08:04, Jean Delvare wrote: > > > On Mon, 06 Jan 2014 18:26:34 -0800, Guenter Roeck wrote: > > >> This needs to be addressed > > >> in the thermal code, for example with dummy declarations if THERMAL=m but > > >> SENSORS_LM75=y. The functions are already declared as dummies if THERMAL_OF=n. > > > > > > This won't fly I'm afraid, the number of hwmon drivers affected will > > > grow in the future and you certainly don't want to have to change the > > > generic thermal code every time a new driver is added/converted. > > > > Agreed > > > > > > > > I've looked at the problem this morning and I will admit I do not even > > > understand what the problem is. In Randy's config, CONFIG_THERMAL_OF=y > > > so both thermal_zone_of_sensor_unregister and > > > thermal_zone_of_sensor_register are built-in. SENSORS_LM75=y so the > > > calls to these functions are built-in too. I just can't see how this > > > can be a problem at link time. Can anyone enlighten me? > > > > I believe the problem is more in the fact that THERMAL_OF is a bool, but > > the way it is in thermal Kconfig, it will link to the thermal module, in > > case CONFIG_THERMAL=m. > > Doh. I've been looking at this for an hour and managed to miss > that :( Thanks for explaining. > > > Thus I am proposing the following, > > which limits the user to have THERMAL_OF only as builtin and whenever > > is selected, it will select THERMAL too. That is: > > > > > > From b643aa260ed4f3514d1ca51b1ecbe4be7652a8d0 Mon Sep 17 00:00:00 2001 > > From: Eduardo Valentin > > Date: Tue, 7 Jan 2014 08:04:02 -0400 > > Subject: [PATCH 1/1] thermal: fix compilation issue on CONFIG_THERMAL_OF > > dependencies > > > > Users of API provided by THERMAL_OF config may suffer when > > CONFIG_THERMAL=y, causing linking issues, such as: > > > > drivers/built-in.o: In function `lm75_remove': > > lm75.c:(.text+0x12bd8c): undefined reference to > > `thermal_zone_of_sensor_unregister' > > drivers/built-in.o: In function `lm75_probe': > > lm75.c:(.text+0x12c123): undefined reference to > > `thermal_zone_of_sensor_register' > > > > Therefore, this patch limits the compilation build to always > > have THERMAL=y, whenever THERMAL_OF=y. In this way, whenever > > the API user is built, if THERMAL_OF=y, the build shall have > > the full thermal support, otherwise, the thermal API will provide > > stubs. > > > > Cc: Zhang Rui > > Cc: linux-pm@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org > > Signed-off-by: Eduardo Valentin > > --- > > drivers/thermal/Kconfig | 29 ++++++++++++++++------------- > > 1 file changed, 16 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > > index 58f98bd..dc315e9 100644 > > --- a/drivers/thermal/Kconfig > > +++ b/drivers/thermal/Kconfig > > @@ -29,19 +29,6 @@ config THERMAL_HWMON > > Say 'Y' here if you want all thermal sensors to > > have hwmon sysfs interface too. > > > > -config THERMAL_OF > > - bool > > - prompt "APIs to parse thermal data out of device tree" > > - depends on OF > > - default y > > - help > > - This options provides helpers to add the support to > > - read and parse thermal data definitions out of the > > - device tree blob. > > - > > - Say 'Y' here if you need to build thermal infrastructure > > - based on device tree. > > - > > choice > > prompt "Default Thermal governor" > > default THERMAL_DEFAULT_GOV_STEP_WISE > > @@ -235,3 +222,19 @@ source "drivers/thermal/samsung/Kconfig" > > endmenu > > > > endif > > + > > +menuconfig THERMAL_OF > > + bool > > + prompt "APIs to parse thermal data out of device tree" > > + depends on OF > > + select THERMAL > > + default y > > + help > > + This options enables DT thermal API which adds support to > > + read and parse thermal data definitions out of the > > + device tree blob. This option is mostly used by embedded > > + thermal drivers. > > + > > + Say 'Y' here if you need to build thermal infrastructure > > + based on device tree. > > + > > I suppose this works, however I believe there is value in allowing for > modular building of as much code as possible. > > I have an alternative proposal, which lets thermal be built as module, > and hopefully also addresses the issue (I can't test...) The only > drawback is that the same dependency must be added for every other > hwmon driver which optionally uses THERMAL_OF. > > From: Jean Delvare > > Based on an earlier attempt by Randy Dunlap. > > Fix SENSORS_LM75 dependencies to eliminate build errors: > > drivers/built-in.o: In function `lm75_remove': > lm75.c:(.text+0x12bd8c): undefined reference to `thermal_zone_of_sensor_unregister' > drivers/built-in.o: In function `lm75_probe': > lm75.c:(.text+0x12c123): undefined reference to `thermal_zone_of_sensor_register' > > Add depends on THERMAL since that is what provides the > register/unregister functions above, but only if THERMAL_OF was > selected as this is an optional feature of the driver. > > Signed-off-by: Jean Delvare > Cc: Randy Dunlap > Cc: Eduardo Valentin Acked-by: Zhang Rui thanks, rui > --- > drivers/hwmon/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > --- linux-3.13-rc7.orig/drivers/hwmon/Kconfig 2014-01-07 09:01:24.812848091 +0100 > +++ linux-3.13-rc7/drivers/hwmon/Kconfig 2014-01-07 15:19:11.039472329 +0100 > @@ -650,6 +650,7 @@ config SENSORS_LM73 > config SENSORS_LM75 > tristate "National Semiconductor LM75 and compatibles" > depends on I2C > + depends on THERMAL || !THERMAL_OF > help > If you say yes here you get support for one common type of > temperature sensor chip, with models including: > > -- 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/