drm/atomic-helper: Export framebuffer_changed()
The Rockchip driver cannot use drm_atomic_helper_wait_for_vblanks()
because it has hardware counters for neither vblanks nor scanlines.
In order to simplify re-implementing the functionality for this driver,
export the framebuffer_changed() helper so it can be reused.
Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 57cccd6..7c52306 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -946,9 +946,23 @@
}
}
-static bool framebuffer_changed(struct drm_device *dev,
- struct drm_atomic_state *old_state,
- struct drm_crtc *crtc)
+/**
+ * drm_atomic_helper_framebuffer_changed - check if framebuffer has changed
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ * @crtc: DRM crtc
+ *
+ * Checks whether the framebuffer used for this CRTC changes as a result of
+ * the atomic update. This is useful for drivers which cannot use
+ * drm_atomic_helper_wait_for_vblanks() and need to reimplement its
+ * functionality.
+ *
+ * Returns:
+ * true if the framebuffer changed.
+ */
+bool drm_atomic_helper_framebuffer_changed(struct drm_device *dev,
+ struct drm_atomic_state *old_state,
+ struct drm_crtc *crtc)
{
struct drm_plane *plane;
struct drm_plane_state *old_plane_state;
@@ -965,6 +979,7 @@
return false;
}
+EXPORT_SYMBOL(drm_atomic_helper_framebuffer_changed);
/**
* drm_atomic_helper_wait_for_vblanks - wait for vblank on crtcs
@@ -999,7 +1014,8 @@
if (old_state->legacy_cursor_update)
continue;
- if (!framebuffer_changed(dev, old_state, crtc))
+ if (!drm_atomic_helper_framebuffer_changed(dev,
+ old_state, crtc))
continue;
ret = drm_crtc_vblank_get(crtc);