drm/i915/dp: Require a valid atomic state for SST link training

After the previous patch link training happens always with a valid
atomic state, so remove the NOTE comments and asserts which required a
valid state only for DP-MST and allowed for a NULL state for DP-SST.
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240712135724.660399-2-imre.deak@intel.com

drivers/gpu/drm/i915/display/intel_dp.c

@@ -2866,7 +2866,6 @@ static void intel_dp_queue_modeset_retry_work(struct intel_connector *connector)
 		drm_connector_put(&connector->base);
 }
 
-/* NOTE: @state is only valid for MST links and can be %NULL for SST. */
 void
 intel_dp_queue_modeset_retry_for_link(struct intel_atomic_state *state,
 				      struct intel_encoder *encoder,
@@ -2875,7 +2874,6 @@ intel_dp_queue_modeset_retry_for_link(struct intel_atomic_state *state,
 	struct intel_connector *connector;
 	struct intel_digital_connector_state *conn_state;
 	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
 	int i;
 
 	if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST)) {
@@ -2884,9 +2882,6 @@ intel_dp_queue_modeset_retry_for_link(struct intel_atomic_state *state,
 		return;
 	}
 
-	if (drm_WARN_ON(&i915->drm, !state))
-		return;
-
 	for_each_new_intel_connector_in_state(state, connector, conn_state, i) {
 		if (!conn_state->base.crtc)
 			continue;

drivers/gpu/drm/i915/display/intel_dp_link_training.c

@@ -1234,12 +1234,10 @@ static int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp,
 	return 0;
 }
 
-/* NOTE: @state is only valid for MST links and can be %NULL for SST. */
 static bool intel_dp_schedule_fallback_link_training(struct intel_atomic_state *state,
 						     struct intel_dp *intel_dp,
 						     const struct intel_crtc_state *crtc_state)
 {
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
 	struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
 
 	if (!intel_digital_port_connected(&dp_to_dig_port(intel_dp)->base)) {
@@ -1255,11 +1253,6 @@ static bool intel_dp_schedule_fallback_link_training(struct intel_atomic_state *
 		return false;
 	}
 
-	if (drm_WARN_ON(&i915->drm,
-			intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST) &&
-			!state))
-		return false;
-
 	/* Schedule a Hotplug Uevent to userspace to start modeset */
 	intel_dp_queue_modeset_retry_for_link(state, encoder, crtc_state);
 
@@ -1518,8 +1511,6 @@ intel_dp_128b132b_link_train(struct intel_dp *intel_dp,
  * retraining with reduced link rate/lane parameters if the link training
  * fails.
  * After calling this function intel_dp_stop_link_train() must be called.
- *
- * NOTE: @state is only valid for MST links and can be %NULL for SST.
  */
 void intel_dp_start_link_train(struct intel_atomic_state *state,
 			       struct intel_dp *intel_dp,
@@ -1536,11 +1527,6 @@ void intel_dp_start_link_train(struct intel_atomic_state *state,
 	 */
 	int lttpr_count = intel_dp_init_lttpr_and_dprx_caps(intel_dp);
 
-	if (drm_WARN_ON(&i915->drm,
-			intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST) &&
-			!state))
-		return;
-
 	if (lttpr_count < 0)
 		/* Still continue with enabling the port and link training. */
 		lttpr_count = 0;