drm/irq: Add drm_crtc_vblank_reset

[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / drm_irq.c

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 4d79dad9d44fad0ac48b2b81177ffda8430b390b..e78a1f5cad9cdb189d597f35e64aedc1d0f80261 100644 (file)
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -778,7 +778,7 @@ static struct timeval get_drm_timestamp(void)
 
 /**
  * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
- *                            vblank interval
+ *                             vblank interval
  * @dev: DRM device
  * @crtc: which CRTC's vblank timestamp to retrieve
  * @tvblank: Pointer to target struct timeval which should receive the timestamp
@@ -933,6 +933,7 @@ void drm_send_vblank_event(struct drm_device *dev, int crtc,
 {
        struct timeval now;
        unsigned int seq;
+
        if (crtc >= 0) {
                seq = drm_vblank_count_and_time(dev, crtc, &now);
        } else {
@@ -1224,6 +1225,38 @@ 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
@@ -1422,7 +1455,7 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
        unsigned int seq;
        int ret;
 
-       e = kzalloc(sizeof *e, GFP_KERNEL);
+       e = kzalloc(sizeof(*e), GFP_KERNEL);
        if (e == NULL) {
                ret = -ENOMEM;
                goto err_put;
@@ -1431,7 +1464,7 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
        e->pipe = pipe;
        e->base.pid = current->pid;
        e->event.base.type = DRM_EVENT_VBLANK;
-       e->event.base.length = sizeof e->event;
+       e->event.base.length = sizeof(e->event);
        e->event.user_data = vblwait->request.signal;
        e->base.event = &e->event.base;
        e->base.file_priv = file_priv;
@@ -1451,12 +1484,12 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
                goto err_unlock;
        }
 
-       if (file_priv->event_space < sizeof e->event) {
+       if (file_priv->event_space < sizeof(e->event)) {
                ret = -EBUSY;
                goto err_unlock;
        }
 
-       file_priv->event_space -= sizeof e->event;
+       file_priv->event_space -= sizeof(e->event);
        seq = drm_vblank_count_and_time(dev, pipe, &now);
 
        if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&