On Tue, Jan 07, 2014 at 12:33:28PM -0400, Eduardo Valentin wrote: > On 07-01-2014 10:21, 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 <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. > >> + > > > > 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 <khali@xxxxxxxxxxxx> > > > > 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 <khali@xxxxxxxxxxxx> > > Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > > Cc: Eduardo Valentin <eduardo.valentin@xxxxxx> > > I agree with this approach, as it can properly serve the purpose of > fixing this specific issue. The only drawback here is the fact that we > need to add this change to every possible user of this API. If you want > to push this fix via hwmon, you can add my > Acked-by: Eduardo Valentin <eduardo.valentin@xxxxxx> > > and I request Rui to drop the patch I sent earlier. > > Now, other issue is the fact that the thermal framework config entry > needs to be revisited, despite the link to this issue. As I mentioned in > other email thread, there are other system requirements that may prevent > proper usage of the thermal framework as a module. This is, I know, > another topic, and it shall be discussed in a different thread. > > > --- > > 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: > > Excellent idea. Looks good to me, only I think you'll need the same for TMP102. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
