drm/tilcdc: Remove drm_framebuffer_get() and *_put() calls

The drm_framebuffer_get() and drm_framebuffer_put() calls in the
tilcdc driver are obsolete. The drm atomic modesetting core should
take care of holding the references while the atomic state object is
in use. The old state is deleted when a commit of a new one is
completed after drm_atomic_helper_wait_for_vblanks().

This also fixes an occasional framebuffer leak the old
drm_framebuffer_get() and drm_framebuffer_put() code had.
Signed-off-by: Jyri Sarha <jsarha@ti.com>

drivers/gpu/drm/tilcdc/tilcdc_crtc.c

@@ -51,12 +51,8 @@ struct tilcdc_crtc {
 	ktime_t last_vblank;
 	unsigned int hvtotal_us;
 
-	struct drm_framebuffer *curr_fb;
 	struct drm_framebuffer *next_fb;
 
-	/* for deferred fb unref's: */
-	struct drm_flip_work unref_work;
-
 	/* Only set if an external encoder is connected */
 	bool simulate_vesa_sync;
 
@@ -70,20 +66,8 @@ struct tilcdc_crtc {
 };
 #define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)
 
-static void unref_worker(struct drm_flip_work *work, void *val)
-{
-	struct tilcdc_crtc *tilcdc_crtc =
-		container_of(work, struct tilcdc_crtc, unref_work);
-	struct drm_device *dev = tilcdc_crtc->base.dev;
-
-	mutex_lock(&dev->mode_config.mutex);
-	drm_framebuffer_put(val);
-	mutex_unlock(&dev->mode_config.mutex);
-}
-
 static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb)
 {
-	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
 	struct drm_device *dev = crtc->dev;
 	struct tilcdc_drm_private *priv = dev->dev_private;
 	struct drm_gem_cma_object *gem;
@@ -108,12 +92,6 @@ static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb)
 
 	dma_base_and_ceiling = (u64)end << 32 | start;
 	tilcdc_write64(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, dma_base_and_ceiling);
-
-	if (tilcdc_crtc->curr_fb)
-		drm_flip_work_queue(&tilcdc_crtc->unref_work,
-			tilcdc_crtc->curr_fb);
-
-	tilcdc_crtc->curr_fb = fb;
 }
 
 /*
@@ -464,8 +442,6 @@ static void tilcdc_crtc_set_mode(struct drm_crtc *crtc)
 
 	set_scanout(crtc, fb);
 
-	drm_framebuffer_get(fb);
-
 	crtc->hwmode = crtc->state->adjusted_mode;
 
 	tilcdc_crtc->hvtotal_us =
@@ -524,7 +500,6 @@ static void tilcdc_crtc_off(struct drm_crtc *crtc, bool shutdown)
 {
 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
 	struct drm_device *dev = crtc->dev;
-	struct tilcdc_drm_private *priv = dev->dev_private;
 	int ret;
 
 	mutex_lock(&tilcdc_crtc->enable_lock);
@@ -554,20 +529,6 @@ static void tilcdc_crtc_off(struct drm_crtc *crtc, bool shutdown)
 
 	pm_runtime_put_sync(dev->dev);
 
-	if (tilcdc_crtc->next_fb) {
-		drm_flip_work_queue(&tilcdc_crtc->unref_work,
-				    tilcdc_crtc->next_fb);
-		tilcdc_crtc->next_fb = NULL;
-	}
-
-	if (tilcdc_crtc->curr_fb) {
-		drm_flip_work_queue(&tilcdc_crtc->unref_work,
-				    tilcdc_crtc->curr_fb);
-		tilcdc_crtc->curr_fb = NULL;
-	}
-
-	drm_flip_work_commit(&tilcdc_crtc->unref_work, priv->wq);
-
 	tilcdc_crtc->enabled = false;
 	mutex_unlock(&tilcdc_crtc->enable_lock);
 }
@@ -614,7 +575,6 @@ static void tilcdc_crtc_recover_work(struct work_struct *work)
 
 static void tilcdc_crtc_destroy(struct drm_crtc *crtc)
 {
-	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
 	struct tilcdc_drm_private *priv = crtc->dev->dev_private;
 
 	tilcdc_crtc_shutdown(crtc);
@@ -623,7 +583,6 @@ static void tilcdc_crtc_destroy(struct drm_crtc *crtc)
 
 	of_node_put(crtc->port);
 	drm_crtc_cleanup(crtc);
-	drm_flip_work_cleanup(&tilcdc_crtc->unref_work);
 }
 
 int tilcdc_crtc_update_fb(struct drm_crtc *crtc,
@@ -638,9 +597,6 @@ int tilcdc_crtc_update_fb(struct drm_crtc *crtc,
 		return -EBUSY;
 	}
 
-	drm_framebuffer_get(fb);
-
-	crtc->primary->fb = fb;
 	tilcdc_crtc->event = event;
 
 	mutex_lock(&tilcdc_crtc->enable_lock);
@@ -936,8 +892,6 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
 
 		now = ktime_get();
 
-		drm_flip_work_commit(&tilcdc_crtc->unref_work, priv->wq);
-
 		spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
 
 		tilcdc_crtc->last_vblank = now;
@@ -1064,9 +1018,6 @@ int tilcdc_crtc_create(struct drm_device *dev)
 
 	init_waitqueue_head(&tilcdc_crtc->frame_done_wq);
 
-	drm_flip_work_init(&tilcdc_crtc->unref_work,
-			"unref", unref_worker);
-
 	spin_lock_init(&tilcdc_crtc->irq_lock);
 	INIT_WORK(&tilcdc_crtc->recover_work, tilcdc_crtc_recover_work);