drm/atomic-helper: Replace drm_atomic_helper_check_crtc_state()

Rename the atomic helper function drm_atomic_helper_check_crtc_state()
to drm_atomic_helper_check_crtc_primary_plane() and only check for an
attached primary plane. Adapt callers.

Instead of having one big function to check for various CRTC state
conditions, we rather want smaller functions that drivers can pick
individually.

v5:
	* rebase on top of udl changes

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221007124338.24152-3-tzimmermann@suse.de

7 files changed, 45 insertions, 46 deletions

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index 8ff998da71ef..d5ee3ad538a8 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -1161,13 +1161,13 @@ static int ast_crtc_helper_atomic_check(struct drm_crtc *crtc,
 	bool succ;
 	int ret;
 
-	ret = drm_atomic_helper_check_crtc_state(crtc_state, false);
-	if (ret)
-		return ret;
-
 	if (!crtc_state->enable)
 		goto out;
 
+	ret = drm_atomic_helper_check_crtc_primary_plane(crtc_state);
+	if (ret)
+		return ret;
+
 	ast_state = to_ast_crtc_state(crtc_state);
 
 	format = ast_state->format;
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 02b4a7dc92f5..1a586b3c454b 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -924,51 +924,35 @@ 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
+ * drm_atomic_helper_check_crtc_primary_plane() - Check CRTC state for primary plane
  * @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.
+ * Checks that a CRTC has at least one primary plane attached to it, which is
+ * a requirement on some hardware. Note that this only involves the CRTC side
+ * of the test. To test if the primary plane is visible or if it can be updated
+ * without the CRTC being enabled, use drm_atomic_helper_check_plane_state() in
+ * the plane's atomic check.
  *
  * RETURNS:
- * Zero if update appears valid, error code on failure
+ * 0 if a primary plane is attached to the CRTC, or an error code otherwise
  */
-int drm_atomic_helper_check_crtc_state(struct drm_crtc_state *crtc_state,
-				       bool can_disable_primary_planes)
+int drm_atomic_helper_check_crtc_primary_plane(struct drm_crtc_state *crtc_state)
 {
-	struct drm_device *dev = crtc_state->crtc->dev;
-
-	if (!crtc_state->enable)
-		return 0;
+	struct drm_crtc *crtc = crtc_state->crtc;
+	struct drm_device *dev = crtc->dev;
+	struct drm_plane *plane;
 
 	/* 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) {
-			if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
-				has_primary_plane = true;
-				break;
-			}
-		}
-		if (!has_primary_plane) {
-			drm_dbg_kms(dev, "Cannot enable CRTC without a primary plane.\n");
-			return -EINVAL;
-		}
+	drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
+		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
+			return 0;
 	}
 
-	return 0;
+	drm_dbg_atomic(dev, "[CRTC:%d:%s] primary plane missing\n", crtc->base.id, crtc->name);
+
+	return -EINVAL;
 }
-EXPORT_SYMBOL(drm_atomic_helper_check_crtc_state);
+EXPORT_SYMBOL(drm_atomic_helper_check_crtc_primary_plane);
 
 /**
  * drm_atomic_helper_check_planes - validate state object for planes changes
diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
index e9f782119d3d..31233c6ae3c4 100644
--- a/drivers/gpu/drm/drm_simple_kms_helper.c
+++ b/drivers/gpu/drm/drm_simple_kms_helper.c
@@ -102,10 +102,14 @@ static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 	int ret;
 
-	ret = drm_atomic_helper_check_crtc_state(crtc_state, false);
+	if (!crtc_state->enable)
+		goto out;
+
+	ret = drm_atomic_helper_check_crtc_primary_plane(crtc_state);
 	if (ret)
 		return ret;
 
+out:
 	return drm_atomic_add_affected_planes(state, crtc);
 }
 
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index bbab2549243a..5f7eb642f0c6 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -579,13 +579,13 @@ int mgag200_crtc_helper_atomic_check(struct drm_crtc *crtc, struct drm_atomic_st
 	struct drm_property_blob *new_gamma_lut = new_crtc_state->gamma_lut;
 	int ret;
 
-	ret = drm_atomic_helper_check_crtc_state(new_crtc_state, false);
-	if (ret)
-		return ret;
-
 	if (!new_crtc_state->enable)
 		return 0;
 
+	ret = drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
+	if (ret)
+		return ret;
+
 	if (new_crtc_state->mode_changed) {
 		if (funcs->pixpllc_atomic_check) {
 			ret = funcs->pixpllc_atomic_check(crtc, new_state);
diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
index f456b233d2e7..57e48355c008 100644
--- a/drivers/gpu/drm/solomon/ssd130x.c
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -651,10 +651,14 @@ static int ssd130x_crtc_helper_atomic_check(struct drm_crtc *crtc,
 	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(new_state, crtc);
 	int ret;
 
-	ret = drm_atomic_helper_check_crtc_state(new_crtc_state, false);
+	if (!new_crtc_state->enable)
+		goto out;
+
+	ret = drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
 	if (ret)
 		return ret;
 
+out:
 	return drm_atomic_add_affected_planes(new_state, crtc);
 }
 
diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c
index 18489779fb8a..ecd49a8f3334 100644
--- a/drivers/gpu/drm/tiny/simpledrm.c
+++ b/drivers/gpu/drm/tiny/simpledrm.c
@@ -551,10 +551,14 @@ static int simpledrm_crtc_helper_atomic_check(struct drm_crtc *crtc,
 	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(new_state, crtc);
 	int ret;
 
-	ret = drm_atomic_helper_check_crtc_state(new_crtc_state, false);
+	if (!new_crtc_state->enable)
+		goto out;
+
+	ret = drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
 	if (ret)
 		return ret;
 
+out:
 	return drm_atomic_add_affected_planes(new_state, crtc);
 }
 
diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index 3a25f3fc2b22..4b79d44752c9 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -315,7 +315,10 @@ static int udl_crtc_helper_atomic_check(struct drm_crtc *crtc, struct drm_atomic
 {
 	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 
-	return drm_atomic_helper_check_crtc_state(new_crtc_state, false);
+	if (!new_crtc_state->enable)
+		return 0;
+
+	return drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
 }
 
 static void udl_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_state *state)