diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 062cbda1bf4a..f4af1ca0fb62 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -123,10 +123,10 @@ module_param_named(preliminary_hw_support, i915_preliminary_hw_support, int, 060
 MODULE_PARM_DESC(preliminary_hw_support,
 		"Enable preliminary hardware support. (default: false)");
 
-int i915_disable_power_well __read_mostly = 0;
+int i915_disable_power_well __read_mostly = 1;
 module_param_named(disable_power_well, i915_disable_power_well, int, 0600);
 MODULE_PARM_DESC(disable_power_well,
-		 "Disable the power well when possible (default: false)");
+		 "Disable the power well when possible (default: true)");
 
 int i915_enable_ips __read_mostly = 1;
 module_param_named(enable_ips, i915_enable_ips, int, 0600);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 4200c32407ec..97afd2639fb6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1880,6 +1880,10 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
 	u32 seqno = intel_ring_get_seqno(ring);
 
 	BUG_ON(ring == NULL);
+	if (obj->ring != ring && obj->last_write_seqno) {
+		/* Keep the seqno relative to the current ring */
+		obj->last_write_seqno = seqno;
+	}
 	obj->ring = ring;
 
 	/* Add a reference if we're newly entering the active list. */
@@ -2653,7 +2657,6 @@ static void i965_write_fence_reg(struct drm_device *dev, int reg,
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	int fence_reg;
 	int fence_pitch_shift;
-	uint64_t val;
 
 	if (INTEL_INFO(dev)->gen >= 6) {
 		fence_reg = FENCE_REG_SANDYBRIDGE_0;
@@ -2663,8 +2666,23 @@ static void i965_write_fence_reg(struct drm_device *dev, int reg,
 		fence_pitch_shift = I965_FENCE_PITCH_SHIFT;
 	}
 
+	fence_reg += reg * 8;
+
+	/* To w/a incoherency with non-atomic 64-bit register updates,
+	 * we split the 64-bit update into two 32-bit writes. In order
+	 * for a partial fence not to be evaluated between writes, we
+	 * precede the update with write to turn off the fence register,
+	 * and only enable the fence as the last step.
+	 *
+	 * For extra levels of paranoia, we make sure each step lands
+	 * before applying the next step.
+	 */
+	I915_WRITE(fence_reg, 0);
+	POSTING_READ(fence_reg);
+
 	if (obj) {
 		u32 size = obj->gtt_space->size;
+		uint64_t val;
 
 		val = (uint64_t)((obj->gtt_offset + size - 4096) &
 				 0xfffff000) << 32;
@@ -2673,12 +2691,16 @@ static void i965_write_fence_reg(struct drm_device *dev, int reg,
 		if (obj->tiling_mode == I915_TILING_Y)
 			val |= 1 << I965_FENCE_TILING_Y_SHIFT;
 		val |= I965_FENCE_REG_VALID;
-	} else
-		val = 0;
 
-	fence_reg += reg * 8;
-	I915_WRITE64(fence_reg, val);
-	POSTING_READ(fence_reg);
+		I915_WRITE(fence_reg + 4, val >> 32);
+		POSTING_READ(fence_reg + 4);
+
+		I915_WRITE(fence_reg + 0, val);
+		POSTING_READ(fence_reg);
+	} else {
+		I915_WRITE(fence_reg + 4, 0);
+		POSTING_READ(fence_reg + 4);
+	}
 }
 
 static void i915_write_fence_reg(struct drm_device *dev, int reg,
@@ -2796,56 +2818,17 @@ static inline int fence_number(struct drm_i915_private *dev_priv,
 	return fence - dev_priv->fence_regs;
 }
 
-struct write_fence {
-	struct drm_device *dev;
-	struct drm_i915_gem_object *obj;
-	int fence;
-};
-
-static void i915_gem_write_fence__ipi(void *data)
-{
-	struct write_fence *args = data;
-
-	/* Required for SNB+ with LLC */
-	wbinvd();
-
-	/* Required for VLV */
-	i915_gem_write_fence(args->dev, args->fence, args->obj);
-}
-
 static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
 					 struct drm_i915_fence_reg *fence,
 					 bool enable)
 {
 	struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
-	struct write_fence args = {
-		.dev = obj->base.dev,
-		.fence = fence_number(dev_priv, fence),
-		.obj = enable ? obj : NULL,
-	};
+	int reg = fence_number(dev_priv, fence);
 
-	/* In order to fully serialize access to the fenced region and
-	 * the update to the fence register we need to take extreme
-	 * measures on SNB+. In theory, the write to the fence register
-	 * flushes all memory transactions before, and coupled with the
-	 * mb() placed around the register write we serialise all memory
-	 * operations with respect to the changes in the tiler. Yet, on
-	 * SNB+ we need to take a step further and emit an explicit wbinvd()
-	 * on each processor in order to manually flush all memory
-	 * transactions before updating the fence register.
-	 *
-	 * However, Valleyview complicates matter. There the wbinvd is
-	 * insufficient and unlike SNB/IVB requires the serialising
-	 * register write. (Note that that register write by itself is
-	 * conversely not sufficient for SNB+.) To compromise, we do both.
-	 */
-	if (INTEL_INFO(args.dev)->gen >= 6)
-		on_each_cpu(i915_gem_write_fence__ipi, &args, 1);
-	else
-		i915_gem_write_fence(args.dev, args.fence, args.obj);
+	i915_gem_write_fence(obj->base.dev, reg, enable ? obj : NULL);
 
 	if (enable) {
-		obj->fence_reg = args.fence;
+		obj->fence_reg = reg;
 		fence->obj = obj;
 		list_move_tail(&fence->lru_list, &dev_priv->mm.fence_list);
 	} else {
@@ -4611,7 +4594,7 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
 	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list)
 		if (obj->pages_pin_count == 0)
 			cnt += obj->base.size >> PAGE_SHIFT;
-	list_for_each_entry(obj, &dev_priv->mm.inactive_list, global_list)
+	list_for_each_entry(obj, &dev_priv->mm.inactive_list, mm_list)
 		if (obj->pin_count == 0 && obj->pages_pin_count == 0)
 			cnt += obj->base.size >> PAGE_SHIFT;
 
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index b73971234013..26e162bb3a51 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -75,7 +75,12 @@ intel_dp_max_link_bw(struct intel_dp *intel_dp)
 	case DP_LINK_BW_1_62:
 	case DP_LINK_BW_2_7:
 		break;
+	case DP_LINK_BW_5_4: /* 1.2 capable displays may advertise higher bw */
+		max_link_bw = DP_LINK_BW_2_7;
+		break;
 	default:
+		WARN(1, "invalid max DP link bw val %x, using 1.62Gbps\n",
+		     max_link_bw);
 		max_link_bw = DP_LINK_BW_1_62;
 		break;
 	}
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index ccbdd83f5220..d10e6735771f 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5500,9 +5500,38 @@ void intel_gt_init(struct drm_device *dev)
 	if (IS_VALLEYVIEW(dev)) {
 		dev_priv->gt.force_wake_get = vlv_force_wake_get;
 		dev_priv->gt.force_wake_put = vlv_force_wake_put;
-	} else if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev)) {
+	} else if (IS_HASWELL(dev)) {
 		dev_priv->gt.force_wake_get = __gen6_gt_force_wake_mt_get;
 		dev_priv->gt.force_wake_put = __gen6_gt_force_wake_mt_put;
+	} else if (IS_IVYBRIDGE(dev)) {
+		u32 ecobus;
+
+		/* IVB configs may use multi-threaded forcewake */
+
+		/* A small trick here - if the bios hasn't configured
+		 * MT forcewake, and if the device is in RC6, then
+		 * force_wake_mt_get will not wake the device and the
+		 * ECOBUS read will return zero. Which will be
+		 * (correctly) interpreted by the test below as MT
+		 * forcewake being disabled.
+		 */
+		mutex_lock(&dev->struct_mutex);
+		__gen6_gt_force_wake_mt_get(dev_priv);
+		ecobus = I915_READ_NOTRACE(ECOBUS);
+		__gen6_gt_force_wake_mt_put(dev_priv);
+		mutex_unlock(&dev->struct_mutex);
+
+		if (ecobus & FORCEWAKE_MT_ENABLE) {
+			dev_priv->gt.force_wake_get =
+						__gen6_gt_force_wake_mt_get;
+			dev_priv->gt.force_wake_put =
+						__gen6_gt_force_wake_mt_put;
+		} else {
+			DRM_INFO("No MT forcewake available on Ivybridge, this can result in issues\n");
+			DRM_INFO("when using vblank-synced partial screen updates.\n");
+			dev_priv->gt.force_wake_get = __gen6_gt_force_wake_get;
+			dev_priv->gt.force_wake_put = __gen6_gt_force_wake_put;
+		}
 	} else if (IS_GEN6(dev)) {
 		dev_priv->gt.force_wake_get = __gen6_gt_force_wake_get;
 		dev_priv->gt.force_wake_put = __gen6_gt_force_wake_put;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index e51ab552046c..664118d8c1d6 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -379,6 +379,17 @@ u32 intel_ring_get_active_head(struct intel_ring_buffer *ring)
 	return I915_READ(acthd_reg);
 }
 
+static void ring_setup_phys_status_page(struct intel_ring_buffer *ring)
+{
+	struct drm_i915_private *dev_priv = ring->dev->dev_private;
+	u32 addr;
+
+	addr = dev_priv->status_page_dmah->busaddr;
+	if (INTEL_INFO(ring->dev)->gen >= 4)
+		addr |= (dev_priv->status_page_dmah->busaddr >> 28) & 0xf0;
+	I915_WRITE(HWS_PGA, addr);
+}
+
 static int init_ring_common(struct intel_ring_buffer *ring)
 {
 	struct drm_device *dev = ring->dev;
@@ -390,6 +401,11 @@ static int init_ring_common(struct intel_ring_buffer *ring)
 	if (HAS_FORCE_WAKE(dev))
 		gen6_gt_force_wake_get(dev_priv);
 
+	if (I915_NEED_GFX_HWS(dev))
+		intel_ring_setup_status_page(ring);
+	else
+		ring_setup_phys_status_page(ring);
+
 	/* Stop the ring if it's running. */
 	I915_WRITE_CTL(ring, 0);
 	I915_WRITE_HEAD(ring, 0);
@@ -518,9 +534,6 @@ cleanup_pipe_control(struct intel_ring_buffer *ring)
 	struct pipe_control *pc = ring->private;
 	struct drm_i915_gem_object *obj;
 
-	if (!ring->private)
-		return;
-
 	obj = pc->obj;
 
 	kunmap(sg_page(obj->pages->sgl));
@@ -528,7 +541,6 @@ cleanup_pipe_control(struct intel_ring_buffer *ring)
 	drm_gem_object_unreference(&obj->base);
 
 	kfree(pc);
-	ring->private = NULL;
 }
 
 static int init_render_ring(struct intel_ring_buffer *ring)
@@ -601,7 +613,10 @@ static void render_ring_cleanup(struct intel_ring_buffer *ring)
 	if (HAS_BROKEN_CS_TLB(dev))
 		drm_gem_object_unreference(to_gem_object(ring->private));
 
-	cleanup_pipe_control(ring);
+	if (INTEL_INFO(dev)->gen >= 5)
+		cleanup_pipe_control(ring);
+
+	ring->private = NULL;
 }
 
 static void
@@ -1223,7 +1238,6 @@ static int init_status_page(struct intel_ring_buffer *ring)
 	ring->status_page.obj = obj;
 	memset(ring->status_page.page_addr, 0, PAGE_SIZE);
 
-	intel_ring_setup_status_page(ring);
 	DRM_DEBUG_DRIVER("%s hws offset: 0x%08x\n",
 			ring->name, ring->status_page.gfx_addr);
 
@@ -1237,10 +1251,9 @@ err:
 	return ret;
 }
 
-static int init_phys_hws_pga(struct intel_ring_buffer *ring)
+static int init_phys_status_page(struct intel_ring_buffer *ring)
 {
 	struct drm_i915_private *dev_priv = ring->dev->dev_private;
-	u32 addr;
 
 	if (!dev_priv->status_page_dmah) {
 		dev_priv->status_page_dmah =
@@ -1249,11 +1262,6 @@ static int init_phys_hws_pga(struct intel_ring_buffer *ring)
 			return -ENOMEM;
 	}
 
-	addr = dev_priv->status_page_dmah->busaddr;
-	if (INTEL_INFO(ring->dev)->gen >= 4)
-		addr |= (dev_priv->status_page_dmah->busaddr >> 28) & 0xf0;
-	I915_WRITE(HWS_PGA, addr);
-
 	ring->status_page.page_addr = dev_priv->status_page_dmah->vaddr;
 	memset(ring->status_page.page_addr, 0, PAGE_SIZE);
 
@@ -1281,7 +1289,7 @@ static int intel_init_ring_buffer(struct drm_device *dev,
 			return ret;
 	} else {
 		BUG_ON(ring->id != RCS);
-		ret = init_phys_hws_pga(ring);
+		ret = init_phys_status_page(ring);
 		if (ret)
 			return ret;
 	}
@@ -1893,7 +1901,7 @@ int intel_render_ring_init_dri(struct drm_device *dev, u64 start, u32 size)
 	}
 
 	if (!I915_NEED_GFX_HWS(dev)) {
-		ret = init_phys_hws_pga(ring);
+		ret = init_phys_status_page(ring);
 		if (ret)
 			return ret;
 	}