Since pm_mutex is not exported using lock/unlock_system_sleep() from
inside a kernel module causes a "pm_mutex undefined" linker error.
Hence move lock/unlock_system_sleep() into kernel/power/main.c and
export these.
Signed-off-by: Bart Van Assche <bart.vanass...@wdc.com>
Cc: Rafael J. Wysocki <r...@rjwysocki.net>
---
include/linux/suspend.h | 28 ++--------------------------
kernel/power/main.c | 29 +++++++++++++++++++++++++++++
2 files changed, 31 insertions(+), 26 deletions(-)
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index d60b0f5c38d5..cc22a24516d6 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -443,32 +443,8 @@ extern bool pm_save_wakeup_count(unsigned int count);
extern void pm_wakep_autosleep_enabled(bool set);
extern void pm_print_active_wakeup_sources(void);
-static inline void lock_system_sleep(void)
-{
- current->flags |= PF_FREEZER_SKIP;
- mutex_lock(&pm_mutex);
-}
-
-static inline void unlock_system_sleep(void)
-{
- /*
- * Don't use freezer_count() because we don't want the call to
- * try_to_freeze() here.
- *
- * Reason:
- * Fundamentally, we just don't need it, because freezing condition
- * doesn't come into effect until we release the pm_mutex lock,
- * since the freezer always works with pm_mutex held.
- *
- * More importantly, in the case of hibernation,
- * unlock_system_sleep() gets called in snapshot_read() and
- * snapshot_write() when the freezing condition is still in effect.
- * Which means, if we use try_to_freeze() here, it would make them
- * enter the refrigerator, thus causing hibernation to lockup.
- */
- current->flags &= ~PF_FREEZER_SKIP;
- mutex_unlock(&pm_mutex);
-}
+extern void lock_system_sleep(void);
+extern void unlock_system_sleep(void);
#else /* !CONFIG_PM_SLEEP */
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 3a2ca9066583..705c2366dafe 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -22,6 +22,35 @@ DEFINE_MUTEX(pm_mutex);
#ifdef CONFIG_PM_SLEEP
+void lock_system_sleep(void)
+{
+ current->flags |= PF_FREEZER_SKIP;
+ mutex_lock(&pm_mutex);
+}
+EXPORT_SYMBOL_GPL(lock_system_sleep);
+
+void unlock_system_sleep(void)
+{
+ /*
+ * Don't use freezer_count() because we don't want the call to
+ * try_to_freeze() here.
+ *
+ * Reason:
+ * Fundamentally, we just don't need it, because freezing condition
+ * doesn't come into effect until we release the pm_mutex lock,
+ * since the freezer always works with pm_mutex held.
+ *
+ * More importantly, in the case of hibernation,
+ * unlock_system_sleep() gets called in snapshot_read() and
+ * snapshot_write() when the freezing condition is still in effect.
+ * Which means, if we use try_to_freeze() here, it would make them
+ * enter the refrigerator, thus causing hibernation to lockup.
+ */
+ current->flags &= ~PF_FREEZER_SKIP;
+ mutex_unlock(&pm_mutex);
+}
+EXPORT_SYMBOL_GPL(unlock_system_sleep);
+
/* Routines for PM-transition notifications */
static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
--
2.15.1
