drm/i915: Zap the GTT mapping when transitioning from untiled to tiled.

As of 52dc7d32b88156248167864f77a9026abe27b432, we could leave an old
linear GTT mapping in place, so that apps trying to GTT-mapped write in
tiled data wouldn't get the fence added, and garbage would get displayed.

Signed-off-by: Eric Anholt <eric@anholt.net>

3 files changed, 8 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 9d6889799d01..d08752875885 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -673,6 +673,7 @@ void i915_gem_free_object(struct drm_gem_object *obj);
 int i915_gem_object_pin(struct drm_gem_object *obj, uint32_t alignment);
 void i915_gem_object_unpin(struct drm_gem_object *obj);
 int i915_gem_object_unbind(struct drm_gem_object *obj);
+void i915_gem_release_mmap(struct drm_gem_object *obj);
 void i915_gem_lastclose(struct drm_device *dev);
 uint32_t i915_get_gem_seqno(struct drm_device *dev);
 int i915_gem_object_get_fence_reg(struct drm_gem_object *obj);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 08d8e5d85955..5bf420378b6d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1266,7 +1266,7 @@ out_free_list:
  * mapping will then trigger a page fault on the next user access, allowing
  * fixup by i915_gem_fault().
  */
-static void
+void
 i915_gem_release_mmap(struct drm_gem_object *obj)
 {
         struct drm_device *dev = obj->dev;
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index daeae62e1c28..a2d527b22ec4 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -521,6 +521,12 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
                         goto err;
                 }
 
+                /* If we've changed tiling, GTT-mappings of the object
+                 * need to re-fault to ensure that the correct fence register
+                 * setup is in place.
+                 */
+                i915_gem_release_mmap(obj);
+
                 obj_priv->tiling_mode = args->tiling_mode;
                 obj_priv->stride = args->stride;
         }