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

Rafael J. Wysocki
2011-03-01T00:12:19Z

On Tuesday, March 01, 2011, Randy Dunlap wrote:
> On 02/28/11 14:42, Rafael J. Wysocki wrote:
> > 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 <mingo@elte.hu> wrote:
> >>>>
> >>>>> * Randy Dunlap <randy.dunlap@oracle.com> 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 <randy.dunlap@oracle.com>
> >>>
> >>> 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.
>
> Looks good, built both with NET=y and NET disabled.
>
> Acked-by: Randy Dunlap <randy.dunlap@oracle.com>

Great, thanks! Below is the same patch with a changelog and sign-off.

Rafael

---
From: Rafael J. Wysocki <rjw@sisk.pl>
Subject: ACPI: Fix build for CONFIG_NET unset

Several ACPI drivers fail to build if CONFIG_NET is unset, because
they refer to things depending on CONFIG_THERMAL that in turn depends
on CONFIG_NET. However, CONFIG_THERMAL doesn't really need to depend
on CONFIG_NET, because the only part of it requiring CONFIG_NET is
the netlink interface in thermal_sys.c.

Put the netlink interface in thermal_sys.c under #ifdef CONFIG_NET
and remove the dependency of CONFIG_THERMAL on CONFIG_NET from
drivers/thermal/Kconfig.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
---
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