drm/i915: create a prepare step for primary planes updates

Take out the pin_fb code so commit phase can't fail anymore.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 848f330..d678bc0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11403,6 +11403,42 @@
 }
 
 static int
+intel_prepare_primary_plane(struct drm_plane *plane,
+			    struct intel_plane_state *state)
+{
+	struct drm_crtc *crtc = state->crtc;
+	struct drm_framebuffer *fb = state->fb;
+	struct drm_device *dev = crtc->dev;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	enum pipe pipe = intel_crtc->pipe;
+	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
+	struct drm_i915_gem_object *old_obj = intel_fb_obj(plane->fb);
+	int ret;
+
+	intel_crtc_wait_for_pending_flips(crtc);
+
+	if (intel_crtc_has_pending_flip(crtc)) {
+		DRM_ERROR("pipe is still busy with an old pageflip\n");
+		return -EBUSY;
+	}
+
+	if (old_obj != obj) {
+		mutex_lock(&dev->struct_mutex);
+		ret = intel_pin_and_fence_fb_obj(dev, obj, NULL);
+		if (ret == 0)
+			i915_gem_track_fb(old_obj, obj,
+					  INTEL_FRONTBUFFER_PRIMARY(pipe));
+		mutex_unlock(&dev->struct_mutex);
+		if (ret != 0) {
+			DRM_DEBUG_KMS("pin & fence failed\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void
 intel_commit_primary_plane(struct drm_plane *plane,
 			   struct intel_plane_state *state)
 {
@@ -11417,27 +11453,6 @@
 	struct drm_i915_gem_object *old_obj = intel_fb_obj(plane->fb);
 	struct intel_plane *intel_plane = to_intel_plane(plane);
 	struct drm_rect *src = &state->src;
-	int ret;
-
-	intel_crtc_wait_for_pending_flips(crtc);
-
-	if (intel_crtc_has_pending_flip(crtc)) {
-		DRM_ERROR("pipe is still busy with an old pageflip\n");
-		return -EBUSY;
-	}
-
-	if (plane->fb != fb) {
-		mutex_lock(&dev->struct_mutex);
-		ret = intel_pin_and_fence_fb_obj(dev, obj, NULL);
-		if (ret == 0)
-			i915_gem_track_fb(old_obj, obj,
-					  INTEL_FRONTBUFFER_PRIMARY(pipe));
-		mutex_unlock(&dev->struct_mutex);
-		if (ret != 0) {
-			DRM_DEBUG_KMS("pin & fence failed\n");
-			return ret;
-		}
-	}
 
 	crtc->primary->fb = fb;
 	crtc->x = src->x1;
@@ -11515,8 +11530,6 @@
 		intel_unpin_fb_obj(old_obj);
 		mutex_unlock(&dev->struct_mutex);
 	}
-
-	return 0;
 }
 
 static int
@@ -11557,6 +11570,10 @@
 	if (ret)
 		return ret;
 
+	ret = intel_prepare_primary_plane(plane, &state);
+	if (ret)
+		return ret;
+
 	intel_commit_primary_plane(plane, &state);
 
 	return 0;