Subject: [PATCH] hwmon/sensors: fix SENSORS_LM75 dependencies

From: Randy Dunlap <[email-masked]>
Date: Mon, 06 Jan 2014 17:09:48 -0800

On 01/06/14 12:32, Guenter Roeck wrote:
> On Mon, Jan 06, 2014 at 11:51:36AM -0800, Randy Dunlap wrote:
>> On 01/06/14 01:40, Stephen Rothwell wrote:
>>> Hi all,
>>>
>>> This tree fails (more than usual) the powerpc allyesconfig build.
>>>
>>> Changes since 20131224:
>>>
>>
>>
>> on i386:
>>
>> 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'
>>
> 
> AFAICS that is a dependency problem in thermal code.
> CONFIG_THERMAL=m defines the symbols, but CONFIG_SENSORS_LM75=y.

CONFIG_THERMAL_OF defines the symbols.

It looks to me like drivers/hwmon/Kconfig SENSORS_LM75 entry needs a
	depends on THERMAL_OF
line, but that won't fix this build error.
The problem (once again, not the first time that I have seen this one) is that
we have a tristate =m that depends on a bool =y.

Hm, I bet a "depends on THERMAL" for SENSORS_LM75 will fix this.
[test]
Yes, that restricts (limits) SENSORS_LM75 to n/m; y is not possible.

Patch for your consideration is below.

> 
> Up to the thermal folks to fix; if the code ends up in mainline we'll have to
> revert the patch introducing the calls to the lm75 driver (and the tmp102 driver
> which has the same issue).
> 
> Another oddity is the help text to THERMAL_OF, which states that it supports
> reading and parsing thermal data definitions out of dt but fails to mention
> that it also provides the above API functions.

---
From: Randy Dunlap <[email-masked]>

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 <[email-masked]>
---
 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: