[PATCH RT 05/22] PM / wakeup: Make events_lock a RAW_SPINLOCK

From: Steven Rostedt
Date: Wed Sep 05 2018 - 08:30:51 EST


4.14.63-rt41-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

[ Upstream commit 1debb85a1d7d5c7655b4574f5b0ddf5f7c84873e ]

The `events_lock' is acquired during suspend while interrupts are
disabled even on RT. The lock is taken only for a very brief moment.
Make it a RAW lock which avoids "sleeping while atomic" warnings on RT.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
drivers/base/power/wakeup.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index cdd6f256da59..2269d379c92f 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -52,7 +52,7 @@ static void split_counters(unsigned int *cnt, unsigned int *inpr)
/* A preserved old value of the events counter. */
static unsigned int saved_count;

-static DEFINE_SPINLOCK(events_lock);
+static DEFINE_RAW_SPINLOCK(events_lock);

static void pm_wakeup_timer_fn(unsigned long data);

@@ -180,9 +180,9 @@ void wakeup_source_add(struct wakeup_source *ws)
ws->active = false;
ws->last_time = ktime_get();

- spin_lock_irqsave(&events_lock, flags);
+ raw_spin_lock_irqsave(&events_lock, flags);
list_add_rcu(&ws->entry, &wakeup_sources);
- spin_unlock_irqrestore(&events_lock, flags);
+ raw_spin_unlock_irqrestore(&events_lock, flags);
}
EXPORT_SYMBOL_GPL(wakeup_source_add);

@@ -197,9 +197,9 @@ void wakeup_source_remove(struct wakeup_source *ws)
if (WARN_ON(!ws))
return;

- spin_lock_irqsave(&events_lock, flags);
+ raw_spin_lock_irqsave(&events_lock, flags);
list_del_rcu(&ws->entry);
- spin_unlock_irqrestore(&events_lock, flags);
+ raw_spin_unlock_irqrestore(&events_lock, flags);
synchronize_srcu(&wakeup_srcu);
}
EXPORT_SYMBOL_GPL(wakeup_source_remove);
@@ -844,7 +844,7 @@ bool pm_wakeup_pending(void)
unsigned long flags;
bool ret = false;

- spin_lock_irqsave(&events_lock, flags);
+ raw_spin_lock_irqsave(&events_lock, flags);
if (events_check_enabled) {
unsigned int cnt, inpr;

@@ -852,7 +852,7 @@ bool pm_wakeup_pending(void)
ret = (cnt != saved_count || inpr > 0);
events_check_enabled = !ret;
}
- spin_unlock_irqrestore(&events_lock, flags);
+ raw_spin_unlock_irqrestore(&events_lock, flags);

if (ret) {
pr_info("PM: Wakeup pending, aborting suspend\n");
@@ -941,13 +941,13 @@ bool pm_save_wakeup_count(unsigned int count)
unsigned long flags;

events_check_enabled = false;
- spin_lock_irqsave(&events_lock, flags);
+ raw_spin_lock_irqsave(&events_lock, flags);
split_counters(&cnt, &inpr);
if (cnt == count && inpr == 0) {
saved_count = count;
events_check_enabled = true;
}
- spin_unlock_irqrestore(&events_lock, flags);
+ raw_spin_unlock_irqrestore(&events_lock, flags);
return events_check_enabled;
}

--
2.18.0