drm/atomic-helper: implement ->page_flip

[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / drm_atomic_helper.c

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 6668d2c9713333fe8ed61675209b75212f338561..a3216a7f7ccc535fa6d4c5e3962930a8e2be5999 100644 (file)
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1620,3 +1620,89 @@ backoff:
        goto retry;
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_set_property);
+
+/**
+ * drm_atomic_helper_page_flip - execute a legacy page flip
+ * @crtc: DRM crtc
+ * @fb: DRM framebuffer
+ * @event: optional DRM event to signal upon completion
+ * @flags: flip flags for non-vblank sync'ed updates
+ *
+ * Provides a default page flip implementation using the atomic driver interface.
+ *
+ * Note that for now so called async page flips (i.e. updates which are not
+ * synchronized to vblank) are not supported, since the atomic interfaces have
+ * no provisions for this yet.
+ *
+ * Returns:
+ * Returns 0 on success, negative errno numbers on failure.
+ */
+int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
+                               struct drm_framebuffer *fb,
+                               struct drm_pending_vblank_event *event,
+                               uint32_t flags)
+{
+       struct drm_plane *plane = crtc->primary;
+       struct drm_atomic_state *state;
+       struct drm_plane_state *plane_state;
+       struct drm_crtc_state *crtc_state;
+       int ret = 0;
+
+       if (flags & DRM_MODE_PAGE_FLIP_ASYNC)
+               return -EINVAL;
+
+       state = drm_atomic_state_alloc(plane->dev);
+       if (!state)
+               return -ENOMEM;
+
+       state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
+retry:
+       crtc_state = drm_atomic_get_crtc_state(state, crtc);
+       if (IS_ERR(crtc_state)) {
+               ret = PTR_ERR(crtc_state);
+               goto fail;
+       }
+       crtc_state->event = event;
+
+       plane_state = drm_atomic_get_plane_state(state, plane);
+       if (IS_ERR(plane_state)) {
+               ret = PTR_ERR(plane_state);
+               goto fail;
+       }
+
+       ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
+       if (ret != 0)
+               goto fail;
+       plane_state->fb = fb;
+
+       ret = drm_atomic_async_commit(state);
+       if (ret != 0)
+               goto fail;
+
+       /* TODO: ->page_flip is the only driver callback where the core
+        * doesn't update plane->fb. For now patch it up here. */
+       plane->fb = plane->state->fb;
+
+       /* Driver takes ownership of state on successful async commit. */
+       return 0;
+fail:
+       if (ret == -EDEADLK)
+               goto backoff;
+
+       drm_atomic_state_free(state);
+
+       return ret;
+backoff:
+       drm_atomic_legacy_backoff(state);
+       drm_atomic_state_clear(state);
+
+       /*
+        * Someone might have exchanged the framebuffer while we dropped locks
+        * in the backoff code. We need to fix up the fb refcount tracking the
+        * core does for us.
+        */
+       plane->old_fb = plane->fb;
+
+       goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_page_flip);