drm/i915: Return error in i915_gem_set_to_gtt_domain if we're not in the GTT.

It's only for flushing caches appropriately for GTT access, not for actually
getting it there.  Prevents potential smashing of cpu read/write domains on
unbound objects.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 174c0c3ba0b0..3fde82be014f 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -435,6 +435,13 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
 #endif
         if (read_domains & I915_GEM_DOMAIN_GTT) {
                 ret = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0);
+
+                /* Silently promote "you're not bound, there was nothing to do"
+                 * to success, since the client was just asking us to
+                 * make sure everything was done.
+                 */
+                if (ret == -EINVAL)
+                        ret = 0;
         } else {
                 ret = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0);
         }
@@ -1304,6 +1311,10 @@ i915_gem_object_set_to_gtt_domain(struct drm_gem_object *obj, int write)
         struct drm_i915_gem_object *obj_priv = obj->driver_private;
         int ret;
 
+        /* Not valid to be called on unbound objects. */
+        if (obj_priv->gtt_space == NULL)
+                return -EINVAL;
+
         i915_gem_object_flush_gpu_write_domain(obj);
         /* Wait on any GPU rendering and flushing to occur. */
         ret = i915_gem_object_wait_rendering(obj);