On 07-01-2014 10:05, Zhang, Rui wrote: > > >> -----Original Message----- >> From: Eduardo Valentin [mailto:eduardo.valentin@xxxxxx] >> Sent: Tuesday, January 07, 2014 8:24 PM >> To: Jean Delvare >> Cc: Guenter Roeck; Randy Dunlap; Stephen Rothwell; linux- >> next@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Frodo Looijaard; >> lm-sensors@xxxxxxxxxxxxxx; Zhang, Rui; Eduardo Valentin; linux- >> pm@xxxxxxxxxxxxxxx >> Subject: Re: [PATCH] hwmon/sensors: fix SENSORS_LM75 dependencies >> Importance: High >> >> 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 <rdunlap@xxxxxxxxxxxxx> >>>>> >>>>> 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 <rdunlap@xxxxxxxxxxxxx> >>>>> --- >>>>> 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 <eduardo.valentin@xxxxxx> >> 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 <rui.zhang@xxxxxxxxx> >> Cc: linux-pm@xxxxxxxxxxxxxxx >> Cc: linux-kernel@xxxxxxxxxxxxxxx >> Signed-off-by: Eduardo Valentin <eduardo.valentin@xxxxxx> >> --- >> 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? >> > The patch looks good to me, will apply it after it has been verified to fix the problem. > BTW, I've been thinking of make CONFIG_THERMAL a bool since long time ago, the only thing that blocks me is that Thermal subsystem needs to register a hwmon device for each thermal zone and CONFIG_HWMON is a tristate. > I agree with the move of having CONFIG_THERMAL as bool. Unless you have use cases where users are dynamically loading and unloading thermal per user demand, which I doubt. > Thanks, > rui >> -- >> You have got to be excited about what you are doing. (L. Lamport) >> >> Eduardo Valentin > > > -- You have got to be excited about what you are doing. (L. Lamport) Eduardo Valentin
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