Subject: Re: [PATCH upstream build breakage] acpi: several drivers depend on NET

From: "Rafael J. Wysocki" <[email-masked]>
Date: Mon, 28 Feb 2011 23:42:59 +0100

On Monday, February 28, 2011, Rafael J. Wysocki wrote:
> On Monday, February 28, 2011, Randy Dunlap wrote:
> > On Tue, 1 Feb 2011 13:03:23 +0100 Ingo Molnar wrote:
> > 
> > > * Ingo Molnar <[email-masked]> wrote:
> > > 
> > > > * Randy Dunlap <[email-masked]> wrote:
> > > > 
> > > > > On Mon, 20 Dec 2010 20:00:13 +1100 Stephen Rothwell wrote:
> > > > > 
> > > > > > Hi all,
> > > > > > 
> > > > > > [The mirroring on kernel.org is running slowly]
> > > > > > 
> > > > > > Changes since 20101217:
> > > > > 
> > > > > ERROR: "thermal_cooling_device_register" [drivers/acpi/video.ko] undefined!
> > > > > ERROR: "thermal_cooling_device_unregister" [drivers/acpi/video.ko] undefined!
> > > > 
> > > > This bug has been reported two months ago, one month ago, it has been ignored twice 
> > > > and now the bug has been pushed upstream and it's triggering there as well.
> > > > 
> > > > What's going on?
> > > 
> > > *Tap*, *tap*, is this thing on? :)
> > > 
> > > acpi-video is still build-broken upstream, as of .38-rc3:
> > > 
> > >    MODPOST 651 modules
> > >  ERROR: "thermal_cooling_device_register" [drivers/acpi/video.ko] undefined!
> > >  ERROR: "thermal_cooling_device_unregister" [drivers/acpi/video.ko] undefined!
> > >  WARNING: modpost: Found 37 section mismatch(es).
> > >  To see full details build your kernel with:
> > >  'make CONFIG_DEBUG_SECTION_MISMATCH=y'
> > >  make[1]: *** [__modpost] Error 1
> > >  make: *** [modules] Error 2
> > > 
> > > Triggers in about 10% of all randconfig builds. Config attached.
> > 
> > 
> > From: Randy Dunlap <[email-masked]>
> > 
> > Several ACPI drivers select THERMAL, but THERMAL depends on NET
> > (for netlink).  Fix build breakage by making the ACPI drivers
> > also depend on NET.
> 
> Well, making ACPI_FAN depend on NET seems to be a kind of an overstretch to me.
> A proper fix would be to disable the netlink interface in THERMAL when
> NET is unset, I guess.  I'll see what can be done to that end (although I had
> hoped that the people who introduced the breakage would handle it).

OK, please check if the appended patch helps.  Admittedly, I only built it
with CONFIG_NET set, so caveat emptor.

Thanks,
Rafael

---
 drivers/thermal/Kconfig       |    1 -
 drivers/thermal/thermal_sys.c |   40 +++++++++++++++++++++-------------------
 include/linux/thermal.h       |    8 ++++++++
 3 files changed, 29 insertions(+), 20 deletions(-)

Index: linux-2.6/drivers/thermal/thermal_sys.c
===================================================================
--- linux-2.6.orig/drivers/thermal/thermal_sys.c
+++ linux-2.6/drivers/thermal/thermal_sys.c
@@ -62,20 +62,6 @@ static DEFINE_MUTEX(thermal_list_lock);
 
 static unsigned int thermal_event_seqnum;
 
-static struct genl_family thermal_event_genl_family = {
-	.id = GENL_ID_GENERATE,
-	.name = THERMAL_GENL_FAMILY_NAME,
-	.version = THERMAL_GENL_VERSION,
-	.maxattr = THERMAL_GENL_ATTR_MAX,
-};
-
-static struct genl_multicast_group thermal_event_mcgrp = {
-	.name = THERMAL_GENL_MCAST_GROUP_NAME,
-};
-
-static int genetlink_init(void);
-static void genetlink_exit(void);
-
 static int get_idr(struct idr *idr, struct mutex *lock, int *id)
 {
 	int err;
@@ -1225,6 +1211,18 @@ void thermal_zone_device_unregister(stru
 
 EXPORT_SYMBOL(thermal_zone_device_unregister);
 
+#ifdef CONFIG_NET
+static struct genl_family thermal_event_genl_family = {
+	.id = GENL_ID_GENERATE,
+	.name = THERMAL_GENL_FAMILY_NAME,
+	.version = THERMAL_GENL_VERSION,
+	.maxattr = THERMAL_GENL_ATTR_MAX,
+};
+
+static struct genl_multicast_group thermal_event_mcgrp = {
+	.name = THERMAL_GENL_MCAST_GROUP_NAME,
+};
+
 int generate_netlink_event(u32 orig, enum events event)
 {
 	struct sk_buff *skb;
@@ -1301,6 +1299,15 @@ static int genetlink_init(void)
 	return result;
 }
 
+static void genetlink_exit(void)
+{
+	genl_unregister_family(&thermal_event_genl_family);
+}
+#else /* !CONFIG_NET */
+static inline int genetlink_init(void) { return 0; }
+static inline void genetlink_exit(void) {}
+#endif /* !CONFIG_NET */
+
 static int __init thermal_init(void)
 {
 	int result = 0;
@@ -1316,11 +1323,6 @@ static int __init thermal_init(void)
 	return result;
 }
 
-static void genetlink_exit(void)
-{
-	genl_unregister_family(&thermal_event_genl_family);
-}
-
 static void __exit thermal_exit(void)
 {
 	class_unregister(&thermal_class);
Index: linux-2.6/include/linux/thermal.h
===================================================================
--- linux-2.6.orig/include/linux/thermal.h
+++ linux-2.6/include/linux/thermal.h
@@ -172,6 +172,14 @@ void thermal_zone_device_update(struct t
 struct thermal_cooling_device *thermal_cooling_device_register(char *, void *,
 		const struct thermal_cooling_device_ops *);
 void thermal_cooling_device_unregister(struct thermal_cooling_device *);
+
+#ifdef CONFIG_NET
 extern int generate_netlink_event(u32 orig, enum events event);
+#else
+static inline int generate_netlink_event(u32 orig, enum events event)
+{
+	return 0;
+}
+#endif
 
 #endif /* __THERMAL_H__ */
Index: linux-2.6/drivers/thermal/Kconfig
===================================================================
--- linux-2.6.orig/drivers/thermal/Kconfig
+++ linux-2.6/drivers/thermal/Kconfig
@@ -4,7 +4,6 @@
 
 menuconfig THERMAL
 	tristate "Generic Thermal sysfs driver"
-	depends on NET
 	help
 	  Generic Thermal Sysfs driver offers a generic mechanism for
 	  thermal management. Usually it's made up of one or more thermal