drm/tilcdc: Do not keep vblank interrupts enabled all the time

END_OF_FRAME interrupts have been enabled all the time since the
beginning of this driver. It is about time to add this feature.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fb87adebaffe8c7cb4fe7e909a45d47af08d7c6e.1602349100.git.jsarha@ti.com

drivers/gpu/drm/tilcdc/tilcdc_crtc.c

@@ -147,12 +147,9 @@ static void tilcdc_crtc_enable_irqs(struct drm_device *dev)
 		tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
 			LCDC_V1_SYNC_LOST_INT_ENA | LCDC_V1_FRAME_DONE_INT_ENA |
 			LCDC_V1_UNDERFLOW_INT_ENA);
-		tilcdc_set(dev, LCDC_DMA_CTRL_REG,
-			LCDC_V1_END_OF_FRAME_INT_ENA);
 	} else {
 		tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG,
 			LCDC_V2_UNDERFLOW_INT_ENA |
-			LCDC_V2_END_OF_FRAME0_INT_ENA |
 			LCDC_FRAME_DONE | LCDC_SYNC_LOST);
 	}
 }
@@ -678,11 +675,44 @@ static int tilcdc_crtc_atomic_check(struct drm_crtc *crtc,
 
 static int tilcdc_crtc_enable_vblank(struct drm_crtc *crtc)
 {
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
+
+	tilcdc_clear_irqstatus(dev, LCDC_END_OF_FRAME0);
+
+	if (priv->rev == 1)
+		tilcdc_set(dev, LCDC_DMA_CTRL_REG,
+			   LCDC_V1_END_OF_FRAME_INT_ENA);
+	else
+		tilcdc_set(dev, LCDC_INT_ENABLE_SET_REG,
+			   LCDC_V2_END_OF_FRAME0_INT_ENA);
+
+	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
+
 	return 0;
 }
 
 static void tilcdc_crtc_disable_vblank(struct drm_crtc *crtc)
 {
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags);
+
+	if (priv->rev == 1)
+		tilcdc_clear(dev, LCDC_DMA_CTRL_REG,
+			     LCDC_V1_END_OF_FRAME_INT_ENA);
+	else
+		tilcdc_clear(dev, LCDC_INT_ENABLE_SET_REG,
+			     LCDC_V2_END_OF_FRAME0_INT_ENA);
+
+	spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags);
 }
 
 static void tilcdc_crtc_reset(struct drm_crtc *crtc)