power: wakeup_reason: make log function work in interrupt context

If log_suspend_abort_reason called in interrupt context, the spinlock
may deadlock.
With https://lkml.org/lkml/2014/9/1/404, wakeup mechanism changed, so
log_suspend_abort_reason can be placed in interrupt context to retrieve
the abort reasons.

Bug: 32371978
Change-Id: I6902770e54b663d21b47289daec19401fc0dbed4
Signed-off-by: Wei Wang <wvw@google.com>

diff --git a/kernel/power/wakeup_reason.c b/kernel/power/wakeup_reason.c
index 538eb7a..20d218a 100644 (file)
--- a/kernel/power/wakeup_reason.c
+++ b/kernel/power/wakeup_reason.c
@@ -436,12 +436,13 @@ bool log_possible_wakeup_reason(int irq,
 void log_suspend_abort_reason(const char *fmt, ...)
 {
        va_list args;
+       unsigned long flags;
 
-       spin_lock(&resume_reason_lock);
+       spin_lock_irqsave(&resume_reason_lock, flags);
 
        //Suspend abort reason has already been logged.
        if (suspend_abort) {
-               spin_unlock(&resume_reason_lock);
+               spin_unlock_irqrestore(&resume_reason_lock, flags);
                return;
        }
 
@@ -450,7 +451,7 @@ void log_suspend_abort_reason(const char *fmt, ...)
        vsnprintf(abort_reason, MAX_SUSPEND_ABORT_LEN, fmt, args);
        va_end(args);
 
-       spin_unlock(&resume_reason_lock);
+       spin_unlock_irqrestore(&resume_reason_lock, flags);
 }
 
 static bool match_node(struct wakeup_irq_node *n, void *_p)
@@ -462,9 +463,10 @@ static bool match_node(struct wakeup_irq_node *n, void *_p)
 int check_wakeup_reason(int irq)
 {
        bool found;
-       spin_lock(&resume_reason_lock);
+       unsigned long flags;
+       spin_lock_irqsave(&resume_reason_lock, flags);
        found = !walk_irq_node_tree(base_irq_nodes, match_node, &irq);
-       spin_unlock(&resume_reason_lock);
+       spin_unlock_irqrestore(&resume_reason_lock, flags);
        return found;
 }
 
@@ -544,11 +546,12 @@ void clear_wakeup_reasons(void)
 static int wakeup_reason_pm_event(struct notifier_block *notifier,
                unsigned long pm_event, void *unused)
 {
+       unsigned long flags;
        switch (pm_event) {
        case PM_SUSPEND_PREPARE:
-               spin_lock(&resume_reason_lock);
+               spin_lock_irqsave(&resume_reason_lock, flags);
                suspend_abort = false;
-               spin_unlock(&resume_reason_lock);
+               spin_unlock_irqrestore(&resume_reason_lock, flags);
                /* monotonic time since boot */
                last_monotime = ktime_get();
                /* monotonic time since boot including the time spent in suspend */