diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt
index 32ac32e773e1..ca44c5820585 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -352,7 +352,8 @@ Being able to mmap an export dma-buf buffer object has 2 main use-cases:
 
    No special interfaces, userspace simply calls mmap on the dma-buf fd, making
    sure that the cache synchronization ioctl (DMA_BUF_IOCTL_SYNC) is *always*
-   used when the access happens. This is discussed next paragraphs.
+   used when the access happens. Note that DMA_BUF_IOCTL_SYNC can fail with
+   -EAGAIN or -EINTR, in which case it must be restarted.
 
    Some systems might need some sort of cache coherency management e.g. when
    CPU and GPU domains are being accessed through dma-buf at the same time. To
@@ -366,10 +367,10 @@ Being able to mmap an export dma-buf buffer object has 2 main use-cases:
        want (with the new data being consumed by the GPU or say scanout device)
      - munmap once you don't need the buffer any more
 
-    Therefore, for correctness and optimal performance, systems with the memory
-    cache shared by the GPU and CPU i.e. the "coherent" and also the
-    "incoherent" are always required to use SYNC_START and SYNC_END before and
-    after, respectively, when accessing the mapped address.
+    For correctness and optimal performance, it is always required to use
+    SYNC_START and SYNC_END before and after, respectively, when accessing the
+    mapped address. Userspace cannot rely on coherent access, even when there
+    are systems where it just works without calling these ioctls.
 
 2. Supporting existing mmap interfaces in importers
 
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 9810d1df0691..4a2c07ee6677 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -259,6 +259,7 @@ static long dma_buf_ioctl(struct file *file,
 	struct dma_buf *dmabuf;
 	struct dma_buf_sync sync;
 	enum dma_data_direction direction;
+	int ret;
 
 	dmabuf = file->private_data;
 
@@ -285,11 +286,11 @@ static long dma_buf_ioctl(struct file *file,
 		}
 
 		if (sync.flags & DMA_BUF_SYNC_END)
-			dma_buf_end_cpu_access(dmabuf, direction);
+			ret = dma_buf_end_cpu_access(dmabuf, direction);
 		else
-			dma_buf_begin_cpu_access(dmabuf, direction);
+			ret = dma_buf_begin_cpu_access(dmabuf, direction);
 
-		return 0;
+		return ret;
 	default:
 		return -ENOTTY;
 	}
@@ -611,15 +612,19 @@ EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);
  * @dmabuf:	[in]	buffer to complete cpu access for.
  * @direction:	[in]	length of range for cpu access.
  *
- * This call must always succeed.
+ * Can return negative error values, returns 0 on success.
  */
-void dma_buf_end_cpu_access(struct dma_buf *dmabuf,
-			    enum dma_data_direction direction)
+int dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+			   enum dma_data_direction direction)
 {
+	int ret = 0;
+
 	WARN_ON(!dmabuf);
 
 	if (dmabuf->ops->end_cpu_access)
-		dmabuf->ops->end_cpu_access(dmabuf, direction);
+		ret = dmabuf->ops->end_cpu_access(dmabuf, direction);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
 
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
index 1ffe9c329c46..d65dcaee3832 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
@@ -558,7 +558,7 @@ static int atmel_hlcdc_plane_atomic_check(struct drm_plane *p,
 	if (!state->base.crtc || !fb)
 		return 0;
 
-	crtc_state = s->state->crtc_states[drm_crtc_index(s->crtc)];
+	crtc_state = drm_atomic_get_existing_crtc_state(s->state, s->crtc);
 	mode = &crtc_state->adjusted_mode;
 
 	state->src_x = s->src_x;
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index a2596eb803fc..8ee1db866e80 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -380,7 +380,6 @@ EXPORT_SYMBOL(drm_atomic_set_mode_prop_for_crtc);
  * drm_atomic_replace_property_blob - replace a blob property
  * @blob: a pointer to the member blob to be replaced
  * @new_blob: the new blob to replace with
- * @expected_size: the expected size of the new blob
  * @replaced: whether the blob has been replaced
  *
  * RETURNS:
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 2bb90faa0ee2..4befe25c81c7 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -67,7 +67,8 @@ drm_atomic_helper_plane_changed(struct drm_atomic_state *state,
 	struct drm_crtc_state *crtc_state;
 
 	if (plane->state->crtc) {
-		crtc_state = state->crtc_states[drm_crtc_index(plane->state->crtc)];
+		crtc_state = drm_atomic_get_existing_crtc_state(state,
+								plane->state->crtc);
 
 		if (WARN_ON(!crtc_state))
 			return;
@@ -76,8 +77,8 @@ drm_atomic_helper_plane_changed(struct drm_atomic_state *state,
 	}
 
 	if (plane_state->crtc) {
-		crtc_state =
-			state->crtc_states[drm_crtc_index(plane_state->crtc)];
+		crtc_state = drm_atomic_get_existing_crtc_state(state,
+								plane_state->crtc);
 
 		if (WARN_ON(!crtc_state))
 			return;
@@ -374,8 +375,8 @@ mode_fixup(struct drm_atomic_state *state)
 		if (!conn_state->crtc || !conn_state->best_encoder)
 			continue;
 
-		crtc_state =
-			state->crtc_states[drm_crtc_index(conn_state->crtc)];
+		crtc_state = drm_atomic_get_existing_crtc_state(state,
+								conn_state->crtc);
 
 		/*
 		 * Each encoder has at most one connector (since we always steal
@@ -679,7 +680,8 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
 		if (!old_conn_state->crtc)
 			continue;
 
-		old_crtc_state = old_state->crtc_states[drm_crtc_index(old_conn_state->crtc)];
+		old_crtc_state = drm_atomic_get_existing_crtc_state(old_state,
+								    old_conn_state->crtc);
 
 		if (!old_crtc_state->active ||
 		    !drm_atomic_crtc_needs_modeset(old_conn_state->crtc->state))
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 1f3eef6fb345..0506016e18e0 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -228,25 +228,20 @@ static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_dire
 	return ret;
 }
 
-static void i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
+static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 	struct drm_device *dev = obj->base.dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
-	bool was_interruptible;
 	int ret;
 
-	mutex_lock(&dev->struct_mutex);
-	was_interruptible = dev_priv->mm.interruptible;
-	dev_priv->mm.interruptible = false;
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret)
+		return ret;
 
 	ret = i915_gem_object_set_to_gtt_domain(obj, false);
-
-	dev_priv->mm.interruptible = was_interruptible;
 	mutex_unlock(&dev->struct_mutex);
 
-	if (unlikely(ret))
-		DRM_ERROR("unable to flush buffer following CPU access; rendering may be corrupt\n");
+	return ret;
 }
 
 static const struct dma_buf_ops i915_dmabuf_ops =  {
diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
index 3cf8aab23a39..af267c35d813 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
@@ -97,11 +97,12 @@ static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
 	return omap_gem_get_pages(obj, &pages, true);
 }
 
-static void omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
-		enum dma_data_direction dir)
+static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
+					  enum dma_data_direction dir)
 {
 	struct drm_gem_object *obj = buffer->priv;
 	omap_gem_put_pages(obj);
+	return 0;
 }
 
 
diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
index c427499133d6..33239a2b264a 100644
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@@ -423,8 +423,8 @@ static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,
 	}
 
 	if (ufb->obj->base.import_attach) {
-		dma_buf_end_cpu_access(ufb->obj->base.import_attach->dmabuf,
-				       DMA_FROM_DEVICE);
+		ret = dma_buf_end_cpu_access(ufb->obj->base.import_attach->dmabuf,
+					     DMA_FROM_DEVICE);
 	}
 
  unlock:
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 0754a37c9674..49436b4510f4 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -1075,14 +1075,16 @@ static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
 	return PTR_ERR_OR_ZERO(vaddr);
 }
 
-static void ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
-				       enum dma_data_direction direction)
+static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+				      enum dma_data_direction direction)
 {
 	struct ion_buffer *buffer = dmabuf->priv;
 
 	mutex_lock(&buffer->lock);
 	ion_buffer_kmap_put(buffer);
 	mutex_unlock(&buffer->lock);
+
+	return 0;
 }
 
 static struct dma_buf_ops dma_buf_ops = {
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 532108ea0c1c..3fe90d494edb 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -94,7 +94,7 @@ struct dma_buf_ops {
 	void (*release)(struct dma_buf *);
 
 	int (*begin_cpu_access)(struct dma_buf *, enum dma_data_direction);
-	void (*end_cpu_access)(struct dma_buf *, enum dma_data_direction);
+	int (*end_cpu_access)(struct dma_buf *, enum dma_data_direction);
 	void *(*kmap_atomic)(struct dma_buf *, unsigned long);
 	void (*kunmap_atomic)(struct dma_buf *, unsigned long, void *);
 	void *(*kmap)(struct dma_buf *, unsigned long);
@@ -224,8 +224,8 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
 				enum dma_data_direction);
 int dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
 			     enum dma_data_direction dir);
-void dma_buf_end_cpu_access(struct dma_buf *dma_buf,
-			    enum dma_data_direction dir);
+int dma_buf_end_cpu_access(struct dma_buf *dma_buf,
+			   enum dma_data_direction dir);
 void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long);
 void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long, void *);
 void *dma_buf_kmap(struct dma_buf *, unsigned long);
diff --git a/include/linux/fence.h b/include/linux/fence.h
index bb522011383b..5aa95eb886f7 100644
--- a/include/linux/fence.h
+++ b/include/linux/fence.h
@@ -292,7 +292,7 @@ static inline bool fence_is_later(struct fence *f1, struct fence *f2)
 	if (WARN_ON(f1->context != f2->context))
 		return false;
 
-	return f1->seqno - f2->seqno < INT_MAX;
+	return (int)(f1->seqno - f2->seqno) > 0;
 }
 
 /**