[PATCH 10/11] drm/atomic: Add current-mode blob to CRTC state

[Daniel Stone]

Add a blob property tracking the current mode to the CRTC state, and
ensure it is properly updated and referenced.

Signed-off-by: Daniel Stone <daniels at collabora.com>
Tested-by: Sean Paul <seanpaul at chromium.org>
---
 drivers/gpu/drm/drm_atomic.c        | 62 +++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_atomic_helper.c | 11 ++++---
 drivers/gpu/drm/drm_crtc.c          |  3 +-
 include/drm/drm_crtc.h              |  3 ++
 4 files changed, 73 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 67c251f..63fc58a 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -301,6 +301,8 @@ EXPORT_SYMBOL(drm_atomic_get_crtc_state);
 int drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
 				 struct drm_display_mode *mode)
 {
+	struct drm_mode_modeinfo umode;
+
 	/* Early return for no change. */
 	if (!mode && !state->enable)
 		return 0;
@@ -308,9 +310,20 @@ int drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
 	    memcmp(&state->mode, mode, sizeof(*mode)) == 0)
 		return 0;
 
+	if (state->mode_blob)
+		drm_property_unreference_blob(state->mode_blob);
+	state->mode_blob = NULL;
 	state->mode_changed = true;
 
 	if (mode) {
+		drm_mode_convert_to_umode(&umode, mode);
+		state->mode_blob =
+			drm_property_create_blob(state->crtc->dev,
+		                                 sizeof(umode),
+		                                 &umode);
+		if (!state->mode_blob)
+			return -ENOMEM;
+
 		drm_mode_copy(&state->mode, mode);
 		state->enable = true;
 	} else {
@@ -330,6 +343,55 @@ int drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
 }
 EXPORT_SYMBOL(drm_atomic_set_mode_for_crtc);
 
+/**
+ * drm_atomic_set_mode_prop_for_crtc - set mode for CRTC
+ * @state: the CRTC whose incoming state to update
+ * @blob: pointer to blob property to use for mode
+ *
+ * Set a mode (originating from a blob property) on the desired CRTC state.
+ * This function will take a reference on the blob property for the CRTC state,
+ * and release the reference held on the state's existing mode property, if any
+ * was set.
+ */
+int drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
+                                      struct drm_property_blob *blob)
+{
+	if (blob == state->mode_blob)
+		return 0;
+
+	if (state->mode_blob)
+		drm_property_unreference_blob(state->mode_blob);
+	state->mode_blob = NULL;
+
+	if (blob) {
+		if (blob->length != sizeof(struct drm_mode_modeinfo) ||
+		    drm_mode_convert_umode(&state->mode,
+		                           (const struct drm_mode_modeinfo *)
+		                            blob->data))
+			return -EINVAL;
+
+		state->mode_blob = drm_property_reference_blob(blob);
+		state->mode_changed = true;
+		state->enable = true;
+	} else {
+		memset(&state->mode, 0, sizeof(state->mode));
+
+		if (state->enable)
+			state->mode_changed = true;
+		state->enable = false;
+		state->active = false;
+	}
+
+	if (state->enable)
+		DRM_DEBUG_ATOMIC("Set [MODE:%s] for CRTC state %p\n",
+				 state->mode.name, state);
+	else
+		DRM_DEBUG_ATOMIC("Set [NOMODE] for CRTC state %p\n",
+				 state);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_set_mode_prop_for_crtc);
 
 /**
  * drm_atomic_crtc_set_property - set property on CRTC
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 70ce243..5d596d9 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -2027,6 +2027,8 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_dpms);
  */
 void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
 {
+	if (crtc->state && crtc->state->mode_blob)
+		drm_property_unreference_blob(crtc->state->mode_blob);
 	kfree(crtc->state);
 	crtc->state = kzalloc(sizeof(*crtc->state), GFP_KERNEL);
 
@@ -2048,6 +2050,8 @@ void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
 {
 	memcpy(state, crtc->state, sizeof(*state));
 
+	if (state->mode_blob)
+		drm_property_reference_blob(state->mode_blob);
 	state->mode_changed = false;
 	state->active_changed = false;
 	state->planes_changed = false;
@@ -2090,11 +2094,8 @@ EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
 void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
 					    struct drm_crtc_state *state)
 {
-	/*
-	 * This is currently a placeholder so that drivers that subclass the
-	 * state will automatically do the right thing if code is ever added
-	 * to this function.
-	 */
+	if (state->mode_blob)
+		drm_property_unreference_blob(state->mode_blob);
 }
 EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
 
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 9263b22..ee87045 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1961,7 +1961,8 @@ int drm_mode_getcrtc(struct drm_device *dev,
 		crtc_resp->x = crtc->primary->state->src_x >> 16;
 		crtc_resp->y = crtc->primary->state->src_y >> 16;
 		if (crtc->state->enable) {
-			drm_mode_convert_to_umode(&crtc_resp->mode, &crtc->state->mode);
+			memcpy(&crtc_resp->mode, &crtc->state->mode_blob->data,
+			       sizeof(crtc_resp->mode));
 			crtc_resp->mode_valid = 1;
 
 		} else {
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 72b60db..c54fa4a 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -299,6 +299,9 @@ struct drm_crtc_state {
 
 	struct drm_display_mode mode;
 
+	/* blob property to expose current mode to atomic userspace */
+	struct drm_property_blob *mode_blob;
+
 	struct drm_pending_vblank_event *event;
 
 	struct drm_atomic_state *state;
-- 
2.4.1