1 files changed, 27 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index d8feb9053e0c..f0519e31543a 100644
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -473,20 +473,37 @@ static u64 get_rc6(struct drm_i915_private *i915)
                 spin_lock_irqsave(&i915->pmu.lock, flags);
                 spin_lock(&kdev->power.lock);
 
-                if (!i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur)
-                        i915->pmu.suspended_jiffies_last =
-                                                kdev->power.suspended_jiffies;
+                /*
+                 * After the above branch intel_runtime_pm_get_if_in_use failed
+                 * to get the runtime PM reference we cannot assume we are in
+                 * runtime suspend since we can either: a) race with coming out
+                 * of it before we took the power.lock, or b) there are other
+                 * states than suspended which can bring us here.
+                 *
+                 * We need to double-check that we are indeed currently runtime
+                 * suspended and if not we cannot do better than report the last
+                 * known RC6 value.
+                 */
+                if (kdev->power.runtime_status == RPM_SUSPENDED) {
+                        if (!i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur)
+                                i915->pmu.suspended_jiffies_last =
+                                                  kdev->power.suspended_jiffies;
 
-                val = kdev->power.suspended_jiffies -
-                      i915->pmu.suspended_jiffies_last;
-                val += jiffies - kdev->power.accounting_timestamp;
+                        val = kdev->power.suspended_jiffies -
+                              i915->pmu.suspended_jiffies_last;
+                        val += jiffies - kdev->power.accounting_timestamp;
 
-                spin_unlock(&kdev->power.lock);
+                        val = jiffies_to_nsecs(val);
+                        val += i915->pmu.sample[__I915_SAMPLE_RC6].cur;
 
-                val = jiffies_to_nsecs(val);
-                val += i915->pmu.sample[__I915_SAMPLE_RC6].cur;
-                i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur = val;
+                        i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur = val;
+                } else if (i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur) {
+                        val = i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur;
+                } else {
+                        val = i915->pmu.sample[__I915_SAMPLE_RC6].cur;
+                }
 
+                spin_unlock(&kdev->power.lock);
                 spin_unlock_irqrestore(&i915->pmu.lock, flags);
         }