[PATCH 2/3] drm/atomic: add drm_atomic_add_affected_planes

[Maarten Lankhorst]

This is a convenience function to add all planes for a crtc,
similar to add_affected_connectors. This will be used in
drm_atomic_helper_check_modeset, but drivers can call it too
when they need to recalculate all state.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/drm_atomic.c | 32 ++++++++++++++++++++++++++++++++
 include/drm/drm_atomic.h     |  4 ++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index cd1b16b25716..c48b7db438b8 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -956,6 +956,38 @@ drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
 EXPORT_SYMBOL(drm_atomic_add_affected_connectors);
 
 /**
+ * drm_atomic_add_affected_planes - add planes for crtc
+ * @state: atomic state
+ * @crtc: DRM crtc
+ *
+ * This function walks the current configuration and adds all planes
+ * currently used by @crtc to the atomic configuration @state.
+ *
+ * Returns:
+ * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
+ * then the w/w mutex code has detected a deadlock and the entire atomic
+ * sequence must be restarted. All other errors are fatal.
+ */
+int
+drm_atomic_add_affected_planes(struct drm_atomic_state *state,
+			       struct drm_crtc *crtc)
+{
+	struct drm_plane *plane;
+
+	WARN_ON(!drm_atomic_get_existing_crtc_state(state, crtc));
+
+	drm_for_each_plane_mask(plane, state->dev, crtc->state->plane_mask) {
+		struct drm_plane_state *plane_state =
+			drm_atomic_get_plane_state(state, plane);
+
+		if (IS_ERR(plane_state))
+			return PTR_ERR(plane_state);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_add_affected_planes);
+
+/**
  * drm_atomic_connectors_for_crtc - count number of connected outputs
  * @state: atomic state
  * @crtc: DRM crtc
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index f0d3a7387d99..e89db0c377ba 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -120,6 +120,10 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 int __must_check
 drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
 				   struct drm_crtc *crtc);
+int __must_check
+drm_atomic_add_affected_planes(struct drm_atomic_state *state,
+			       struct drm_crtc *crtc);
+
 int
 drm_atomic_connectors_for_crtc(struct drm_atomic_state *state,
 			       struct drm_crtc *crtc);
-- 
2.1.0