On 07-01-2014 08:04, Jean Delvare wrote: > Hi Guenter, Randy, > > On Mon, 06 Jan 2014 18:26:34 -0800, Guenter Roeck wrote: >> On 01/06/2014 05:09 PM, Randy Dunlap wrote: >>> From: 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_OF since that is what provides the >>> register/unregister functions above. >>> >>> Add depends on THERMAL since THERMAL is a tristate (while THERMAL_OF >>> is a bool) and SENSORS_LM75 (tristate) needs to be limited to modular >>> builds when THERMAL=m. >>> >>> Signed-off-by: Randy Dunlap >>> --- >>> drivers/hwmon/Kconfig | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> --- linux-next-20140106.orig/drivers/hwmon/Kconfig >>> +++ linux-next-20140106/drivers/hwmon/Kconfig >>> @@ -650,6 +650,8 @@ config SENSORS_LM73 >>> config SENSORS_LM75 >>> tristate "National Semiconductor LM75 and compatibles" >>> depends on I2C >>> + depends on THERMAL >>> + depends on THERMAL_OF >>> help >>> If you say yes here you get support for one common type of >>> temperature sensor chip, with models including: >>> >>> >> NACK. The driver does not and must not depend on THERMAL. > > Correct. > >> 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. 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. + -- 1.8.2.1.342.gfa7285d Randy, can you please confirm if this fix the issue for you? -- You have got to be excited about what you are doing. (L. Lamport) Eduardo Valentin