drm/i915: enable vblank interrupt on ironlake

so far vblank interrupt on ironlake is disabled, this would cause
bad gfx performance if userspace calls drm_wait_vblank. This patch
enables vblank interrupt on ironlake and follows vblank get/put
model.
Signed-off-by: Li Peng <peng.li@intel.com>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/i915_irq.c

@@ -309,6 +309,12 @@ irqreturn_t ironlake_irq_handler(struct drm_device *dev)
 	if (de_iir & DE_GSE)
 		ironlake_opregion_gse_intr(dev);
 
+	if (de_iir & DE_PIPEA_VBLANK)
+		drm_handle_vblank(dev, 0);
+
+	if (de_iir & DE_PIPEB_VBLANK)
+		drm_handle_vblank(dev, 1);
+
 	/* check event from PCH */
 	if ((de_iir & DE_PCH_EVENT) &&
 	    (pch_iir & SDE_HOTPLUG_MASK)) {
@@ -844,11 +850,11 @@ int i915_enable_vblank(struct drm_device *dev, int pipe)
 	if (!(pipeconf & PIPEACONF_ENABLE))
 		return -EINVAL;
 
-	if (IS_IRONLAKE(dev))
-		return 0;
-
 	spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
-	if (IS_I965G(dev))
+	if (IS_IRONLAKE(dev))
+		ironlake_enable_display_irq(dev_priv, (pipe == 0) ? 
+					    DE_PIPEA_VBLANK: DE_PIPEB_VBLANK);
+	else if (IS_I965G(dev))
 		i915_enable_pipestat(dev_priv, pipe,
 				     PIPE_START_VBLANK_INTERRUPT_ENABLE);
 	else
@@ -866,13 +872,14 @@ void i915_disable_vblank(struct drm_device *dev, int pipe)
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 	unsigned long irqflags;
 
-	if (IS_IRONLAKE(dev))
-		return;
-
 	spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
-	i915_disable_pipestat(dev_priv, pipe,
-			      PIPE_VBLANK_INTERRUPT_ENABLE |
-			      PIPE_START_VBLANK_INTERRUPT_ENABLE);
+	if (IS_IRONLAKE(dev))
+		ironlake_disable_display_irq(dev_priv, (pipe == 0) ? 
+					     DE_PIPEA_VBLANK: DE_PIPEB_VBLANK);
+	else
+		i915_disable_pipestat(dev_priv, pipe,
+				      PIPE_VBLANK_INTERRUPT_ENABLE |
+				      PIPE_START_VBLANK_INTERRUPT_ENABLE);
 	spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 }
 
@@ -1015,7 +1022,8 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 	/* enable kind of interrupts always enabled */
-	u32 display_mask = DE_MASTER_IRQ_CONTROL | DE_GSE | DE_PCH_EVENT;
+	u32 display_mask = DE_MASTER_IRQ_CONTROL | DE_GSE | DE_PCH_EVENT |
+			   DE_PIPEA_VBLANK | DE_PIPEB_VBLANK;
 	u32 render_mask = GT_USER_INTERRUPT;
 	u32 hotplug_mask = SDE_CRT_HOTPLUG | SDE_PORTB_HOTPLUG |
 			   SDE_PORTC_HOTPLUG | SDE_PORTD_HOTPLUG;

drivers/gpu/drm/i915/intel_display.c

@@ -1638,6 +1638,7 @@ static void ironlake_crtc_dpms(struct drm_crtc *crtc, int mode)
 	case DRM_MODE_DPMS_OFF:
 		DRM_DEBUG_KMS("crtc %d dpms off\n", pipe);
 
+		drm_vblank_off(dev, pipe);
 		/* Disable display plane */
 		temp = I915_READ(dspcntr_reg);
 		if ((temp & DISPLAY_PLANE_ENABLE) != 0) {