Add drm_atomic_helper_check_crtc_state(), which contains tests common
to many CRTCs. The first added test verifies that an enabled CRTC has
at least one enabled primary plane.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/gpu/drm/drm_atomic_helper.c | 55 +++++++++++++++++++++++++++++
include/drm/drm_atomic_helper.h | 2 ++
2 files changed, 57 insertions(+)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 987e4b212e9f..329d8a3c3d65 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -875,6 +875,61 @@ int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
}
EXPORT_SYMBOL(drm_atomic_helper_check_plane_state);
+/**
+ * drm_atomic_helper_check_crtc_state() - Check CRTC state for validity
+ * @crtc_state: CRTC state to check
+ * @can_disable_primary_planes: can the CRTC be enabled without a primary plane?
+ *
+ * Checks that a desired CRTC update is valid. Drivers that provide
+ * their own CRTC handling rather than helper-provided implementations may
+ * still wish to call this function to avoid duplication of error checking
+ * code.
+ *
+ * Note that @can_disable_primary_planes only tests if the CRTC can be
+ * enabled without a primary plane. To test if a primary plane can be updated
+ * without a CRTC, use drm_atomic_helper_check_plane_state() in the plane's
+ * atomic check.
+ *
+ * RETURNS:
+ * Zero if update appears valid, error code on failure
+ */
+int drm_atomic_helper_check_crtc_state(struct drm_crtc_state *crtc_state,
+ bool can_disable_primary_planes)
+{
+ struct drm_device *dev = crtc_state->crtc->dev;
+ struct drm_atomic_state *state = crtc_state->state;
+
+ if (!crtc_state->enable)
+ return 0;
+
+ /* needs at least one primary plane to be enabled */
+ if (!can_disable_primary_planes) {
+ bool has_primary_plane = false;
+ struct drm_plane *plane;
+
+ drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
+ struct drm_plane_state *plane_state;
+
+ if (plane->type != DRM_PLANE_TYPE_PRIMARY)
+ continue;
+ plane_state = drm_atomic_get_plane_state(state, plane);
+ if (IS_ERR(plane_state))
+ return PTR_ERR(plane_state);
+ if (plane_state->fb && plane_state->crtc) {
+ has_primary_plane = true;
+ break;
+ }
+ }
+ if (!has_primary_plane) {
+ drm_dbg_kms(dev, "Cannot enable CRTC without a primary plane.\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_atomic_helper_check_crtc_state);
+
/**
* drm_atomic_helper_check_planes - validate state object for planes changes
* @dev: DRM device
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 4045e2507e11..2a0b17842402 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -46,6 +46,8 @@ int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
int max_scale,
bool can_position,
bool can_update_disabled);
+int drm_atomic_helper_check_crtc_state(struct drm_crtc_state *crtc_state,
+ bool can_disable_primary_plane);
int drm_atomic_helper_check_planes(struct drm_device *dev,
struct drm_atomic_state *state);
int drm_atomic_helper_check(struct drm_device *dev,
--
2.36.1
