cpuidle / sleep: Do sanity checks in cpuidle_enter_freeze() too

Modify cpuidle_enter_freeze() to do the sanity checks done by
cpuidle_select() to avoid crashing the suspend-to-idle code
path in case something is missing.

Fixes: 381063133246 (PM / sleep: Re-implement suspend-to-idle handling)
Original-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

1 files changed, 16 insertions, 7 deletions

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index b573f584b15a..8b3e132b6a01 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -44,6 +44,12 @@ void disable_cpuidle(void)
         off = 1;
 }
 
+static bool cpuidle_not_available(struct cpuidle_driver *drv,
+                                  struct cpuidle_device *dev)
+{
+        return off || !initialized || !drv || !dev || !dev->enabled;
+}
+
 /**
  * cpuidle_play_dead - cpu off-lining
  *
@@ -126,6 +132,9 @@ void cpuidle_enter_freeze(void)
         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
         int index;
 
+        if (cpuidle_not_available(drv, dev))
+                goto fallback;
+
         /*
          * Find the deepest state with ->enter_freeze present, which guarantees
          * that interrupts won't be enabled when it exits and allows the tick to
@@ -143,10 +152,13 @@ void cpuidle_enter_freeze(void)
          * at all and try to enter it normally.
          */
         index = cpuidle_find_deepest_state(drv, dev, false);
-        if (index >= 0)
+        if (index >= 0) {
                 cpuidle_enter(drv, dev, index);
-        else
-                arch_cpu_idle();
+                return;
+        }
+
+ fallback:
+        arch_cpu_idle();
 }
 
 /**
@@ -205,12 +217,9 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
  */
 int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 {
-        if (off || !initialized)
+        if (cpuidle_not_available(drv, dev))
                 return -ENODEV;
 
-        if (!drv || !dev || !dev->enabled)
-                return -EBUSY;
-
         return cpuidle_curr_governor->select(drv, dev);
 }