diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c3b9fcf..6446911 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2200,6 +2200,7 @@
 
 int i915_gem_request_alloc(struct intel_engine_cs *ring,
 			   struct intel_context *ctx);
+void i915_gem_request_cancel(struct drm_i915_gem_request *req);
 void i915_gem_request_free(struct kref *req_ref);
 
 static inline uint32_t
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 80b509b..b9e0989 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2485,6 +2485,13 @@
 	} else
 		ringbuf = ring->buffer;
 
+	/*
+	 * To ensure that this call will not fail, space for its emissions
+	 * should already have been reserved in the ring buffer. Let the ring
+	 * know that it is time to use that space up.
+	 */
+	intel_ring_reserved_space_use(ringbuf);
+
 	request_start = intel_ring_get_tail(ringbuf);
 	/*
 	 * Emit any outstanding flushes - execbuf can fail to emit the flush
@@ -2567,6 +2574,9 @@
 			   round_jiffies_up_relative(HZ));
 	intel_mark_busy(dev_priv->dev);
 
+	/* Sanity check that the reserved size was large enough. */
+	intel_ring_reserved_space_end(ringbuf);
+
 	return 0;
 }
 
@@ -2665,6 +2675,26 @@
 	if (ret)
 		goto err;
 
+	/*
+	 * Reserve space in the ring buffer for all the commands required to
+	 * eventually emit this request. This is to guarantee that the
+	 * i915_add_request() call can't fail. Note that the reserve may need
+	 * to be redone if the request is not actually submitted straight
+	 * away, e.g. because a GPU scheduler has deferred it.
+	 *
+	 * Note further that this call merely notes the reserve request. A
+	 * subsequent call to *_ring_begin() is required to actually ensure
+	 * that the reservation is available. Without the begin, if the
+	 * request creator immediately submitted the request without adding
+	 * any commands to it then there might not actually be sufficient
+	 * room for the submission commands. Unfortunately, the current
+	 * *_ring_begin() implementations potentially call back here to
+	 * i915_gem_request_alloc(). Thus calling _begin() here would lead to
+	 * infinite recursion! Until that back call path is removed, it is
+	 * necessary to do a manual _begin() outside.
+	 */
+	intel_ring_reserved_space_reserve(req->ringbuf, MIN_SPACE_FOR_ADD_REQUEST);
+
 	ring->outstanding_lazy_request = req;
 	return 0;
 
@@ -2673,6 +2703,13 @@
 	return ret;
 }
 
+void i915_gem_request_cancel(struct drm_i915_gem_request *req)
+{
+	intel_ring_reserved_space_cancel(req->ringbuf);
+
+	i915_gem_request_unreference(req);
+}
+
 struct drm_i915_gem_request *
 i915_gem_find_active_request(struct intel_engine_cs *ring)
 {
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 2b65d29..7451f38 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -686,6 +686,9 @@
 	unsigned space;
 	int ret;
 
+	/* The whole point of reserving space is to not wait! */
+	WARN_ON(ringbuf->reserved_in_use);
+
 	if (intel_ring_space(ringbuf) >= bytes)
 		return 0;
 
@@ -746,6 +749,9 @@
 	uint32_t __iomem *virt;
 	int rem = ringbuf->size - ringbuf->tail;
 
+	/* Can't wrap if space has already been reserved! */
+	WARN_ON(ringbuf->reserved_in_use);
+
 	if (ringbuf->space < rem) {
 		int ret = logical_ring_wait_for_space(ringbuf, ctx, rem);
 
@@ -769,10 +775,25 @@
 {
 	int ret;
 
+	/*
+	 * Add on the reserved size to the request to make sure that after
+	 * the intended commands have been emitted, there is guaranteed to
+	 * still be enough free space to send them to the hardware.
+	 */
+	if (!ringbuf->reserved_in_use)
+		bytes += ringbuf->reserved_size;
+
 	if (unlikely(ringbuf->tail + bytes > ringbuf->effective_size)) {
 		ret = logical_ring_wrap_buffer(ringbuf, ctx);
 		if (unlikely(ret))
 			return ret;
+
+		if(ringbuf->reserved_size) {
+			uint32_t size = ringbuf->reserved_size;
+
+			intel_ring_reserved_space_cancel(ringbuf);
+			intel_ring_reserved_space_reserve(ringbuf, size);
+		}
 	}
 
 	if (unlikely(ringbuf->space < bytes)) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index b70d25b..0c2bf0e 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2113,6 +2113,9 @@
 	unsigned space;
 	int ret;
 
+	/* The whole point of reserving space is to not wait! */
+	WARN_ON(ringbuf->reserved_in_use);
+
 	if (intel_ring_space(ringbuf) >= n)
 		return 0;
 
@@ -2140,6 +2143,9 @@
 	struct intel_ringbuffer *ringbuf = ring->buffer;
 	int rem = ringbuf->size - ringbuf->tail;
 
+	/* Can't wrap if space has already been reserved! */
+	WARN_ON(ringbuf->reserved_in_use);
+
 	if (ringbuf->space < rem) {
 		int ret = ring_wait_for_space(ring, rem);
 		if (ret)
@@ -2190,16 +2196,77 @@
 	return 0;
 }
 
-static int __intel_ring_prepare(struct intel_engine_cs *ring,
-				int bytes)
+void intel_ring_reserved_space_reserve(struct intel_ringbuffer *ringbuf, int size)
+{
+	/* NB: Until request management is fully tidied up and the OLR is
+	 * removed, there are too many ways for get false hits on this
+	 * anti-recursion check! */
+	/*WARN_ON(ringbuf->reserved_size);*/
+	WARN_ON(ringbuf->reserved_in_use);
+
+	ringbuf->reserved_size = size;
+
+	/*
+	 * Really need to call _begin() here but that currently leads to
+	 * recursion problems! This will be fixed later but for now just
+	 * return and hope for the best. Note that there is only a real
+	 * problem if the create of the request never actually calls _begin()
+	 * but if they are not submitting any work then why did they create
+	 * the request in the first place?
+	 */
+}
+
+void intel_ring_reserved_space_cancel(struct intel_ringbuffer *ringbuf)
+{
+	WARN_ON(ringbuf->reserved_in_use);
+
+	ringbuf->reserved_size   = 0;
+	ringbuf->reserved_in_use = false;
+}
+
+void intel_ring_reserved_space_use(struct intel_ringbuffer *ringbuf)
+{
+	WARN_ON(ringbuf->reserved_in_use);
+
+	ringbuf->reserved_in_use = true;
+	ringbuf->reserved_tail   = ringbuf->tail;
+}
+
+void intel_ring_reserved_space_end(struct intel_ringbuffer *ringbuf)
+{
+	WARN_ON(!ringbuf->reserved_in_use);
+	WARN(ringbuf->tail > ringbuf->reserved_tail + ringbuf->reserved_size,
+	     "request reserved size too small: %d vs %d!\n",
+	     ringbuf->tail - ringbuf->reserved_tail, ringbuf->reserved_size);
+
+	ringbuf->reserved_size   = 0;
+	ringbuf->reserved_in_use = false;
+}
+
+static int __intel_ring_prepare(struct intel_engine_cs *ring, int bytes)
 {
 	struct intel_ringbuffer *ringbuf = ring->buffer;
 	int ret;
 
+	/*
+	 * Add on the reserved size to the request to make sure that after
+	 * the intended commands have been emitted, there is guaranteed to
+	 * still be enough free space to send them to the hardware.
+	 */
+	if (!ringbuf->reserved_in_use)
+		bytes += ringbuf->reserved_size;
+
 	if (unlikely(ringbuf->tail + bytes > ringbuf->effective_size)) {
 		ret = intel_wrap_ring_buffer(ring);
 		if (unlikely(ret))
 			return ret;
+
+		if(ringbuf->reserved_size) {
+			uint32_t size = ringbuf->reserved_size;
+
+			intel_ring_reserved_space_cancel(ringbuf);
+			intel_ring_reserved_space_reserve(ringbuf, size);
+		}
 	}
 
 	if (unlikely(ringbuf->space < bytes)) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 6485029..73db3ae 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -106,6 +106,9 @@
 	int space;
 	int size;
 	int effective_size;
+	int reserved_size;
+	int reserved_tail;
+	bool reserved_in_use;
 
 	/** We track the position of the requests in the ring buffer, and
 	 * when each is retired we increment last_retired_head as the GPU
@@ -472,4 +475,26 @@
 	return ring->outstanding_lazy_request;
 }
 
+/*
+ * Arbitrary size for largest possible 'add request' sequence. The code paths
+ * are complex and variable. Empirical measurement shows that the worst case
+ * is ILK at 136 words. Reserving too much is better than reserving too little
+ * as that allows for corner cases that might have been missed. So the figure
+ * has been rounded up to 160 words.
+ */
+#define MIN_SPACE_FOR_ADD_REQUEST	160
+
+/*
+ * Reserve space in the ring to guarantee that the i915_add_request() call
+ * will always have sufficient room to do its stuff. The request creation
+ * code calls this automatically.
+ */
+void intel_ring_reserved_space_reserve(struct intel_ringbuffer *ringbuf, int size);
+/* Cancel the reservation, e.g. because the request is being discarded. */
+void intel_ring_reserved_space_cancel(struct intel_ringbuffer *ringbuf);
+/* Use the reserved space - for use by i915_add_request() only. */
+void intel_ring_reserved_space_use(struct intel_ringbuffer *ringbuf);
+/* Finish with the reserved space - for use by i915_add_request() only. */
+void intel_ring_reserved_space_end(struct intel_ringbuffer *ringbuf);
+
 #endif /* _INTEL_RINGBUFFER_H_ */