4 files changed, 27 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 9b2048c7077d..4b03dce93859 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2738,6 +2738,8 @@ static void i915_gem_reset_ring_status(struct drm_i915_private *dev_priv,
 static void i915_gem_reset_ring_cleanup(struct drm_i915_private *dev_priv,
 					struct intel_engine_cs *ring)
 {
+	struct intel_ringbuffer *buffer;
+
 	while (!list_empty(&ring->active_list)) {
 		struct drm_i915_gem_object *obj;
 
@@ -2788,6 +2790,18 @@ static void i915_gem_reset_ring_cleanup(struct drm_i915_private *dev_priv,
 
 		i915_gem_request_retire(request);
 	}
+
+	/* Having flushed all requests from all queues, we know that all
+	 * ringbuffers must now be empty. However, since we do not reclaim
+	 * all space when retiring the request (to prevent HEADs colliding
+	 * with rapid ringbuffer wraparound) the amount of available space
+	 * upon reset is less than when we start. Do one more pass over
+	 * all the ringbuffers to reset last_retired_head.
+	 */
+	list_for_each_entry(buffer, &ring->buffers, link) {
+		buffer->last_retired_head = buffer->tail;
+		intel_ring_update_space(buffer);
+	}
 }
 
 void i915_gem_reset(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 14bdb36deb94..fd7b8c9fdfb4 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1897,6 +1897,7 @@ static int logical_ring_init(struct drm_device *dev, struct intel_engine_cs *rin
 	i915_gem_batch_pool_init(dev, &ring->batch_pool);
 	init_waitqueue_head(&ring->irq_queue);
 
+	INIT_LIST_HEAD(&ring->buffers);
 	INIT_LIST_HEAD(&ring->execlist_queue);
 	INIT_LIST_HEAD(&ring->execlist_retired_req_list);
 	spin_lock_init(&ring->execlist_lock);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 69286c9f2fd3..8d6d2de19dca 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2102,10 +2102,14 @@ intel_engine_create_ringbuffer(struct intel_engine_cs *engine, int size)
 	int ret;
 
 	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
-	if (ring == NULL)
+	if (ring == NULL) {
+		DRM_DEBUG_DRIVER("Failed to allocate ringbuffer %s\n",
+				 engine->name);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	ring->ring = engine;
+	list_add(&ring->link, &engine->buffers);
 
 	ring->size = size;
 	/* Workaround an erratum on the i830 which causes a hang if
@@ -2121,8 +2125,9 @@ intel_engine_create_ringbuffer(struct intel_engine_cs *engine, int size)
 
 	ret = intel_alloc_ringbuffer_obj(engine->dev, ring);
 	if (ret) {
-		DRM_ERROR("Failed to allocate ringbuffer %s: %d\n",
-			  engine->name, ret);
+		DRM_DEBUG_DRIVER("Failed to allocate ringbuffer %s: %d\n",
+				 engine->name, ret);
+		list_del(&ring->link);
 		kfree(ring);
 		return ERR_PTR(ret);
 	}
@@ -2134,6 +2139,7 @@ void
 intel_ringbuffer_free(struct intel_ringbuffer *ring)
 {
 	intel_destroy_ringbuffer_obj(ring);
+	list_del(&ring->link);
 	kfree(ring);
 }
 
@@ -2149,6 +2155,7 @@ static int intel_init_ring_buffer(struct drm_device *dev,
 	INIT_LIST_HEAD(&ring->active_list);
 	INIT_LIST_HEAD(&ring->request_list);
 	INIT_LIST_HEAD(&ring->execlist_queue);
+	INIT_LIST_HEAD(&ring->buffers);
 	i915_gem_batch_pool_init(dev, &ring->batch_pool);
 	memset(ring->semaphore.sync_seqno, 0, sizeof(ring->semaphore.sync_seqno));
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 49fa41dc0eb6..58b1976a7d0a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -100,6 +100,7 @@ struct intel_ringbuffer {
 	void __iomem *virtual_start;
 
 	struct intel_engine_cs *ring;
+	struct list_head link;
 
 	u32 head;
 	u32 tail;
@@ -157,6 +158,7 @@ struct  intel_engine_cs {
 	u32		mmio_base;
 	struct		drm_device *dev;
 	struct intel_ringbuffer *buffer;
+	struct list_head buffers;
 
 	/*
 	 * A pool of objects to use as shadow copies of client batch buffers