---

yaml
---
r: 306991
b: refs/heads/master
c: 8489731
h: refs/heads/master
i:
  306989: a27f071
  306987: 97deb6d
  306983: c020181
  306975: c3ac899
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6d5cd9cb1e32e4f4e4468704430b26bcb0bfb129
+refs/heads/master: 8489731c9bd22c27ab17a2190cd7444604abf95f

trunk/drivers/gpu/drm/i915/i915_gem.c

@@ -304,12 +304,25 @@ i915_gem_shmem_pread(struct drm_device *dev,
 	int shmem_page_offset, page_length, ret = 0;
 	int obj_do_bit17_swizzling, page_do_bit17_swizzling;
 	int hit_slowpath = 0;
+	int needs_clflush = 0;
 
 	user_data = (char __user *) (uintptr_t) args->data_ptr;
 	remain = args->size;
 
 	obj_do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj);
 
+	if (!(obj->base.read_domains & I915_GEM_DOMAIN_CPU)) {
+		/* If we're not in the cpu read domain, set ourself into the gtt
+		 * read domain and manually flush cachelines (if required). This
+		 * optimizes for the case when the gpu will dirty the data
+		 * anyway again before the next pread happens. */
+		if (obj->cache_level == I915_CACHE_NONE)
+			needs_clflush = 1;
+		ret = i915_gem_object_set_to_gtt_domain(obj, false);
+		if (ret)
+			return ret;
+	}
+
 	offset = args->offset;
 
 	while (remain > 0) {
@@ -337,6 +350,9 @@ i915_gem_shmem_pread(struct drm_device *dev,
 
 		if (!page_do_bit17_swizzling) {
 			vaddr = kmap_atomic(page);
+			if (needs_clflush)
+				drm_clflush_virt_range(vaddr + shmem_page_offset,
+						       page_length);
 			ret = __copy_to_user_inatomic(user_data,
 						      vaddr + shmem_page_offset,
 						      page_length);
@@ -350,6 +366,10 @@ i915_gem_shmem_pread(struct drm_device *dev,
 		mutex_unlock(&dev->struct_mutex);
 
 		vaddr = kmap(page);
+		if (needs_clflush)
+			drm_clflush_virt_range(vaddr + shmem_page_offset,
+					       page_length);
+
 		if (page_do_bit17_swizzling)
 			ret = __copy_to_user_swizzled(user_data,
 						      vaddr, shmem_page_offset,
@@ -430,12 +450,6 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
 
 	trace_i915_gem_object_pread(obj, args->offset, args->size);
 
-	ret = i915_gem_object_set_cpu_read_domain_range(obj,
-							args->offset,
-							args->size);
-	if (ret)
-		goto out;
-
 	ret = i915_gem_shmem_pread(dev, obj, args, file);
 
 out: