1 files changed, 46 insertions, 10 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index c9f5453f20e7..c8a34476570a 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -276,7 +276,6 @@ static void vblank_disable_fn(unsigned long arg)
 void drm_vblank_cleanup(struct drm_device *dev)
 {
         int crtc;
-        unsigned long irqflags;
 
         /* Bail if the driver didn't call drm_vblank_init() */
         if (dev->num_crtcs == 0)
@@ -285,11 +284,10 @@ void drm_vblank_cleanup(struct drm_device *dev)
         for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
                 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
 
-                del_timer_sync(&vblank->disable_timer);
+                WARN_ON(vblank->enabled &&
+                        drm_core_check_feature(dev, DRIVER_MODESET));
 
-                spin_lock_irqsave(&dev->vbl_lock, irqflags);
-                vblank_disable_and_save(dev, crtc);
-                spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+                del_timer_sync(&vblank->disable_timer);
         }
 
         kfree(dev->vblank);
@@ -475,17 +473,23 @@ int drm_irq_uninstall(struct drm_device *dev)
         dev->irq_enabled = false;
 
         /*
-         * Wake up any waiters so they don't hang.
+         * Wake up any waiters so they don't hang. This is just to paper over
+         * isssues for UMS drivers which aren't in full control of their
+         * vblank/irq handling. KMS drivers must ensure that vblanks are all
+         * disabled when uninstalling the irq handler.
          */
         if (dev->num_crtcs) {
                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
                 for (i = 0; i < dev->num_crtcs; i++) {
                         struct drm_vblank_crtc *vblank = &dev->vblank[i];
 
+                        if (!vblank->enabled)
+                                continue;
+
+                        WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
+
+                        vblank_disable_and_save(dev, i);
                         wake_up(&vblank->queue);
-                        vblank->enabled = false;
-                        vblank->last =
-                                dev->driver->get_vblank_counter(dev, i);
                 }
                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
         }
@@ -1233,6 +1237,38 @@ void drm_crtc_vblank_off(struct drm_crtc *crtc)
 EXPORT_SYMBOL(drm_crtc_vblank_off);
 
 /**
+ * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
+ * @crtc: CRTC in question
+ *
+ * Drivers can use this function to reset the vblank state to off at load time.
+ * Drivers should use this together with the drm_crtc_vblank_off() and
+ * drm_crtc_vblank_on() functions. The difference compared to
+ * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
+ * and hence doesn't need to call any driver hooks.
+ */
+void drm_crtc_vblank_reset(struct drm_crtc *drm_crtc)
+{
+        struct drm_device *dev = drm_crtc->dev;
+        unsigned long irqflags;
+        int crtc = drm_crtc_index(drm_crtc);
+        struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
+
+        spin_lock_irqsave(&dev->vbl_lock, irqflags);
+        /*
+         * Prevent subsequent drm_vblank_get() from enabling the vblank
+         * interrupt by bumping the refcount.
+         */
+        if (!vblank->inmodeset) {
+                atomic_inc(&vblank->refcount);
+                vblank->inmodeset = 1;
+        }
+        spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+        WARN_ON(!list_empty(&dev->vblank_event_list));
+}
+EXPORT_SYMBOL(drm_crtc_vblank_reset);
+
+/**
  * drm_vblank_on - enable vblank events on a CRTC
  * @dev: DRM device
  * @crtc: CRTC in question
@@ -1653,7 +1689,7 @@ bool drm_handle_vblank(struct drm_device *dev, int crtc)
         struct timeval tvblank;
         unsigned long irqflags;
 
-        if (!dev->num_crtcs)
+        if (WARN_ON_ONCE(!dev->num_crtcs))
                 return false;
 
         if (WARN_ON(crtc >= dev->num_crtcs))