1 files changed, 79 insertions, 18 deletions

diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 08f809371bbd..c29577d7a35a 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -94,7 +94,7 @@ static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
         spin_lock_init(&rpm->debug.lock);
 }
 
-static noinline void
+static noinline depot_stack_handle_t
 track_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
 {
         struct i915_runtime_pm *rpm = &i915->runtime_pm;
@@ -105,11 +105,11 @@ track_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
         assert_rpm_wakelock_held(i915);
 
         if (!HAS_RUNTIME_PM(i915))
-                return;
+                return -1;
 
         stack = __save_depot_stack();
         if (!stack)
-                return;
+                return -1;
 
         spin_lock_irqsave(&rpm->debug.lock, flags);
 
@@ -122,9 +122,57 @@ track_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
         if (stacks) {
                 stacks[rpm->debug.count++] = stack;
                 rpm->debug.owners = stacks;
+        } else {
+                stack = -1;
         }
 
         spin_unlock_irqrestore(&rpm->debug.lock, flags);
+
+        return stack;
+}
+
+static void cancel_intel_runtime_pm_wakeref(struct drm_i915_private *i915,
+                                            depot_stack_handle_t stack)
+{
+        struct i915_runtime_pm *rpm = &i915->runtime_pm;
+        unsigned long flags, n;
+        bool found = false;
+
+        if (unlikely(stack == -1))
+                return;
+
+        spin_lock_irqsave(&rpm->debug.lock, flags);
+        for (n = rpm->debug.count; n--; ) {
+                if (rpm->debug.owners[n] == stack) {
+                        memmove(rpm->debug.owners + n,
+                                rpm->debug.owners + n + 1,
+                                (--rpm->debug.count - n) * sizeof(stack));
+                        found = true;
+                        break;
+                }
+        }
+        spin_unlock_irqrestore(&rpm->debug.lock, flags);
+
+        if (WARN(!found,
+                 "Unmatched wakeref (tracking %lu), count %u\n",
+                 rpm->debug.count, atomic_read(&rpm->wakeref_count))) {
+                char *buf;
+
+                buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+                if (!buf)
+                        return;
+
+                __print_depot_stack(stack, buf, PAGE_SIZE, 2);
+                DRM_DEBUG_DRIVER("wakeref %x from\n%s", stack, buf);
+
+                stack = READ_ONCE(rpm->debug.last_release);
+                if (stack) {
+                        __print_depot_stack(stack, buf, PAGE_SIZE, 2);
+                        DRM_DEBUG_DRIVER("wakeref last released at\n%s", buf);
+                }
+
+                kfree(buf);
+        }
 }
 
 static int cmphandle(const void *_a, const void *_b)
@@ -249,10 +297,12 @@ static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
 {
 }
 
-static void track_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
+static depot_stack_handle_t
+track_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
 {
         atomic_inc(&i915->runtime_pm.wakeref_count);
         assert_rpm_wakelock_held(i915);
+        return -1;
 }
 
 static void untrack_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
@@ -1852,7 +1902,7 @@ bool intel_display_power_get_if_enabled(struct drm_i915_private *dev_priv,
         mutex_unlock(&power_domains->lock);
 
         if (!is_enabled)
-                intel_runtime_pm_put(dev_priv);
+                intel_runtime_pm_put_unchecked(dev_priv);
 
         return is_enabled;
 }
@@ -1886,7 +1936,7 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 
         mutex_unlock(&power_domains->lock);
 
-        intel_runtime_pm_put(dev_priv);
+        intel_runtime_pm_put_unchecked(dev_priv);
 }
 
 #define I830_PIPES_POWER_DOMAINS (              \
@@ -3994,7 +4044,7 @@ void intel_power_domains_init_hw(struct drm_i915_private *dev_priv, bool resume)
 void intel_power_domains_fini_hw(struct drm_i915_private *dev_priv)
 {
         /* Keep the power well enabled, but cancel its rpm wakeref. */
-        intel_runtime_pm_put(dev_priv);
+        intel_runtime_pm_put_unchecked(dev_priv);
 
         /* Remove the refcount we took to keep power well support disabled. */
         if (!i915_modparams.disable_power_well)
@@ -4207,8 +4257,10 @@ static void intel_power_domains_verify_state(struct drm_i915_private *dev_priv)
  *
  * Any runtime pm reference obtained by this function must have a symmetric
  * call to intel_runtime_pm_put() to release the reference again.
+ *
+ * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
  */
-void intel_runtime_pm_get(struct drm_i915_private *i915)
+intel_wakeref_t intel_runtime_pm_get(struct drm_i915_private *i915)
 {
         struct pci_dev *pdev = i915->drm.pdev;
         struct device *kdev = &pdev->dev;
@@ -4217,7 +4269,7 @@ void intel_runtime_pm_get(struct drm_i915_private *i915)
         ret = pm_runtime_get_sync(kdev);
         WARN_ONCE(ret < 0, "pm_runtime_get_sync() failed: %d\n", ret);
 
-        track_intel_runtime_pm_wakeref(i915);
+        return track_intel_runtime_pm_wakeref(i915);
 }
 
 /**
@@ -4231,9 +4283,10 @@ void intel_runtime_pm_get(struct drm_i915_private *i915)
  * Any runtime pm reference obtained by this function must have a symmetric
  * call to intel_runtime_pm_put() to release the reference again.
  *
- * Returns: True if the wakeref was acquired, or False otherwise.
+ * Returns: the wakeref cookie to pass to intel_runtime_pm_put(), evaluates
+ * as True if the wakeref was acquired, or False otherwise.
  */
-bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *i915)
+intel_wakeref_t intel_runtime_pm_get_if_in_use(struct drm_i915_private *i915)
 {
         if (IS_ENABLED(CONFIG_PM)) {
                 struct pci_dev *pdev = i915->drm.pdev;
@@ -4246,12 +4299,10 @@ bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *i915)
                  * atm to the late/early system suspend/resume handlers.
                  */
                 if (pm_runtime_get_if_in_use(kdev) <= 0)
-                        return false;
+                        return 0;
         }
 
-        track_intel_runtime_pm_wakeref(i915);
-
-        return true;
+        return track_intel_runtime_pm_wakeref(i915);
 }
 
 /**
@@ -4270,8 +4321,10 @@ bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *i915)
  *
  * Any runtime pm reference obtained by this function must have a symmetric
  * call to intel_runtime_pm_put() to release the reference again.
+ *
+ * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
  */
-void intel_runtime_pm_get_noresume(struct drm_i915_private *i915)
+intel_wakeref_t intel_runtime_pm_get_noresume(struct drm_i915_private *i915)
 {
         struct pci_dev *pdev = i915->drm.pdev;
         struct device *kdev = &pdev->dev;
@@ -4279,7 +4332,7 @@ void intel_runtime_pm_get_noresume(struct drm_i915_private *i915)
         assert_rpm_wakelock_held(i915);
         pm_runtime_get_noresume(kdev);
 
-        track_intel_runtime_pm_wakeref(i915);
+        return track_intel_runtime_pm_wakeref(i915);
 }
 
 /**
@@ -4290,7 +4343,7 @@ void intel_runtime_pm_get_noresume(struct drm_i915_private *i915)
  * intel_runtime_pm_get() and might power down the corresponding
  * hardware block right away if this is the last reference.
  */
-void intel_runtime_pm_put(struct drm_i915_private *i915)
+void intel_runtime_pm_put_unchecked(struct drm_i915_private *i915)
 {
         struct pci_dev *pdev = i915->drm.pdev;
         struct device *kdev = &pdev->dev;
@@ -4301,6 +4354,14 @@ void intel_runtime_pm_put(struct drm_i915_private *i915)
         pm_runtime_put_autosuspend(kdev);
 }
 
+#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
+void intel_runtime_pm_put(struct drm_i915_private *i915, intel_wakeref_t wref)
+{
+        cancel_intel_runtime_pm_wakeref(i915, wref);
+        intel_runtime_pm_put_unchecked(i915);
+}
+#endif
+
 /**
  * intel_runtime_pm_enable - enable runtime pm
  * @i915: i915 device instance