[PATCH 6/6] drm/i915/dp: Track available DP MST vcpi time slots

[Dhinakaran Pandiyan]

Make use of the added MST helpers to find, allocate and release link bw
for atomic modesets.

Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 39 +++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/i915/intel_dp_mst.c  | 36 ++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/i915/intel_drv.h     |  3 +++
 3 files changed, 76 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ab72858..71e2ac7 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14072,6 +14072,40 @@ static int calc_watermark_data(struct drm_atomic_state *state)
 	return 0;
 }
 
+static int intel_mst_clear_config(struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+	struct drm_connector *connector;
+	struct drm_connector_state *connector_state;
+	int i, j;
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		if (!crtc_state->active_changed || crtc_state->active)
+			continue;
+
+		for_each_connector_in_state(state, connector, connector_state, j) {
+			struct intel_encoder *encoder;
+			struct drm_crtc *curr_crtc;
+			int slots;
+
+			encoder = to_intel_encoder(connector->state->best_encoder);
+			if (encoder->type != INTEL_OUTPUT_DP_MST)
+				continue;
+
+			curr_crtc = connector->state->crtc;
+			if (curr_crtc && crtc == curr_crtc) {
+				slots = to_intel_crtc_state(crtc->state)->dp_m_n.tu;
+				return intel_dp_mst_reset_vcpi(encoder,
+							       connector_state,
+							       slots);
+			}
+		}
+	}
+
+	return 0;
+}
+
 /**
  * intel_atomic_check - validate state object
  * @dev: drm device
@@ -14142,8 +14176,11 @@ static int intel_atomic_check(struct drm_device *dev,
 	}
 
 	if (any_ms) {
-		ret = intel_modeset_checks(state);
+		ret = intel_mst_clear_config(state);
+		if (ret)
+			return ret;
 
+		ret = intel_modeset_checks(state);
 		if (ret)
 			return ret;
 	} else {
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 02a1e2c..331909b 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -44,6 +44,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 	int lane_count, slots;
 	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
 	int mst_pbn;
+	struct drm_dp_mst_topology_state *topology_state;
 
 	pipe_config->has_pch_encoder = false;
 	bpp = 24;
@@ -65,7 +66,18 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 	mst_pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock, bpp);
 
 	pipe_config->pbn = mst_pbn;
-	slots = drm_dp_find_vcpi_slots(&intel_dp->mst_mgr, mst_pbn);
+
+	topology_state = drm_atomic_get_mst_topology_state(state,
+							   &intel_dp->mst_mgr);
+	if (topology_state == NULL)
+		return false;
+
+	slots = drm_dp_atomic_find_vcpi_slots(topology_state, connector->port,
+					      mst_pbn);
+	if (slots < 0) {
+		DRM_DEBUG_KMS("not enough link bw for this mode\n");
+		return false;
+	}
 
 	intel_link_compute_m_n(bpp, lane_count,
 			       adjusted_mode->crtc_clock,
@@ -78,6 +90,28 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 
 }
 
+int intel_dp_mst_reset_vcpi(struct intel_encoder *encoder,
+			     struct drm_connector_state *conn_state, int slots)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct drm_dp_mst_topology_mgr *mgr  = &intel_mst->primary->dp.mst_mgr;
+	struct drm_dp_mst_topology_state *topology_state;
+	struct intel_connector *connector =
+		to_intel_connector(conn_state->connector);
+	int released;
+
+	topology_state = drm_atomic_get_mst_topology_state(conn_state->state, mgr);
+	if (IS_ERR(topology_state))
+		return PTR_ERR(topology_state);
+
+	released = drm_dp_atomic_release_vcpi_slots(topology_state, connector->port);
+
+	if (WARN_ON(released != slots))
+		return -EINVAL;
+
+	return 0;
+}
+
 static void intel_mst_disable_dp(struct intel_encoder *encoder,
 				 struct intel_crtc_state *old_crtc_state,
 				 struct drm_connector_state *old_conn_state)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 6b02dac..ea2e41e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1487,6 +1487,9 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector);
 /* intel_dp_mst.c */
 int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
 void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
+int intel_dp_mst_reset_vcpi(struct intel_encoder *encoder,
+			     struct drm_connector_state *conn_state,
+			     int slots);
 /* intel_dsi.c */
 void intel_dsi_init(struct drm_i915_private *dev_priv);
 
-- 
2.7.4