diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 33525c922218c8397ca22c313c68f02c9b0b79d0..7e2b476df744c0a87fa8d6ec1b5d333badb933e6 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1350,17 +1350,25 @@ void i915_hangcheck_elapsed(unsigned long data)
 		i915_seqno_passed(i915_get_gem_seqno(dev,
 				&dev_priv->render_ring),
 			i915_get_tail_request(dev)->seqno)) {
+		bool missed_wakeup = false;
+
 		dev_priv->hangcheck_count = 0;
 
 		/* Issue a wake-up to catch stuck h/w. */
-		if (dev_priv->render_ring.waiting_gem_seqno |
-		    dev_priv->bsd_ring.waiting_gem_seqno) {
-			DRM_ERROR("Hangcheck timer elapsed... GPU idle, missed IRQ.\n");
-			if (dev_priv->render_ring.waiting_gem_seqno)
-				DRM_WAKEUP(&dev_priv->render_ring.irq_queue);
-			if (dev_priv->bsd_ring.waiting_gem_seqno)
-				DRM_WAKEUP(&dev_priv->bsd_ring.irq_queue);
+		if (dev_priv->render_ring.waiting_gem_seqno &&
+		    waitqueue_active(&dev_priv->render_ring.irq_queue)) {
+			DRM_WAKEUP(&dev_priv->render_ring.irq_queue);
+			missed_wakeup = true;
+		}
+
+		if (dev_priv->bsd_ring.waiting_gem_seqno &&
+		    waitqueue_active(&dev_priv->bsd_ring.irq_queue)) {
+			DRM_WAKEUP(&dev_priv->bsd_ring.irq_queue);
+			missed_wakeup = true;
 		}
+
+		if (missed_wakeup)
+			DRM_ERROR("Hangcheck timer elapsed... GPU idle, missed IRQ.\n");
 		return;
 	}
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index fbf58e0f25889aa284cc3c76bbf0cd51bf308463..db22a23c65a2e73e94423f2e52d34c28ea4a5451 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2215,9 +2215,17 @@
 #define  WM1_LP_SR_EN		(1<<31)
 #define  WM1_LP_LATENCY_SHIFT	24
 #define  WM1_LP_LATENCY_MASK	(0x7f<<24)
+#define  WM1_LP_FBC_LP1_MASK	(0xf<<20)
+#define  WM1_LP_FBC_LP1_SHIFT	20
 #define  WM1_LP_SR_MASK		(0x1ff<<8)
 #define  WM1_LP_SR_SHIFT	8
 #define  WM1_LP_CURSOR_MASK	(0x3f)
+#define WM2_LP_ILK		0x4510c
+#define  WM2_LP_EN		(1<<31)
+#define WM3_LP_ILK		0x45110
+#define  WM3_LP_EN		(1<<31)
+#define WM1S_LP_ILK		0x45120
+#define  WM1S_LP_EN		(1<<31)
 
 /* Memory latency timer register */
 #define MLTR_ILK		0x11222
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5279b0c88e9cf500d7c464a962f71e8c4167a50a..2e9191d77127d3b3f8916cc5ad20406bb53e850b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3516,8 +3516,7 @@ static void ironlake_update_wm(struct drm_device *dev,  int planea_clock,
 		reg_value = I915_READ(WM1_LP_ILK);
 		reg_value &= ~(WM1_LP_LATENCY_MASK | WM1_LP_SR_MASK |
 			       WM1_LP_CURSOR_MASK);
-		reg_value |= WM1_LP_SR_EN |
-			     (ilk_sr_latency << WM1_LP_LATENCY_SHIFT) |
+		reg_value |= (ilk_sr_latency << WM1_LP_LATENCY_SHIFT) |
 			     (sr_wm << WM1_LP_SR_SHIFT) | cursor_wm;
 
 		I915_WRITE(WM1_LP_ILK, reg_value);
@@ -5839,6 +5838,9 @@ void intel_init_clock_gating(struct drm_device *dev)
 			I915_WRITE(DISP_ARB_CTL,
 					(I915_READ(DISP_ARB_CTL) |
 						DISP_FBC_WM_DIS));
+		I915_WRITE(WM3_LP_ILK, 0);
+		I915_WRITE(WM2_LP_ILK, 0);
+		I915_WRITE(WM1_LP_ILK, 0);
 		}
 		/*
 		 * Based on the document from hardware guys the following bits