drm/i915/dp: Use check link state work in the hotplug handler

Simplify things by retraining a DP link if a bad link is detected in the
hotplug handler from the encoder's check link state work, similarly to
how this is done after a modeset link training failure.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610164933.2947366-12-imre.deak@intel.com

drivers/gpu/drm/i915/display/g4x_dp.c

@@ -1160,9 +1160,7 @@ intel_dp_hotplug(struct intel_encoder *encoder,
 		 struct intel_connector *connector)
 {
 	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
-	struct drm_modeset_acquire_ctx ctx;
 	enum intel_hotplug_state state;
-	int ret;
 
 	if (intel_dp->compliance.test_active &&
 	    intel_dp->compliance.test_type == DP_TEST_LINK_PHY_TEST_PATTERN) {
@@ -1173,23 +1171,7 @@ intel_dp_hotplug(struct intel_encoder *encoder,
 
 	state = intel_encoder_hotplug(encoder, connector);
 
-	drm_modeset_acquire_init(&ctx, 0);
-
-	for (;;) {
-		ret = intel_dp_retrain_link(encoder, &ctx);
-
-		if (ret == -EDEADLK) {
-			drm_modeset_backoff(&ctx);
-			continue;
-		}
-
-		break;
-	}
-
-	drm_modeset_drop_locks(&ctx);
-	drm_modeset_acquire_fini(&ctx);
-	drm_WARN(encoder->base.dev, ret,
-		 "Acquiring modeset locks failed with %i\n", ret);
+	intel_dp_check_link_state(intel_dp);
 
 	/*
 	 * Keeping it consistent with intel_ddi_hotplug() and

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

@@ -4558,14 +4558,13 @@ intel_ddi_hotplug(struct intel_encoder *encoder,
 	state = intel_encoder_hotplug(encoder, connector);
 
 	if (!intel_tc_port_link_reset(dig_port)) {
-		intel_modeset_lock_ctx_retry(&ctx, NULL, 0, ret) {
-			if (connector->base.connector_type == DRM_MODE_CONNECTOR_HDMIA)
+		if (connector->base.connector_type == DRM_MODE_CONNECTOR_HDMIA) {
+			intel_modeset_lock_ctx_retry(&ctx, NULL, 0, ret)
 				ret = intel_hdmi_reset_link(encoder, &ctx);
-			else
-				ret = intel_dp_retrain_link(encoder, &ctx);
+			drm_WARN_ON(encoder->base.dev, ret);
+		} else {
+			intel_dp_check_link_state(intel_dp);
 		}
-
-		drm_WARN_ON(encoder->base.dev, ret);
 	}
 
 	/*

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

@@ -5271,6 +5271,20 @@ void intel_dp_link_check(struct intel_encoder *encoder)
 	drm_WARN_ON(&i915->drm, ret);
 }
 
+void intel_dp_check_link_state(struct intel_dp *intel_dp)
+{
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct intel_encoder *encoder = &dig_port->base;
+
+	if (!intel_dp_is_connected(intel_dp))
+		return;
+
+	if (!intel_dp_needs_link_retrain(intel_dp))
+		return;
+
+	intel_encoder_link_check_queue_work(encoder, 0);
+}
+
 static int intel_dp_prep_phy_test(struct intel_dp *intel_dp,
 				  struct drm_modeset_acquire_ctx *ctx,
 				  u8 *pipe_mask)

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

@@ -60,6 +60,7 @@ int intel_dp_get_active_pipes(struct intel_dp *intel_dp,
 int intel_dp_retrain_link(struct intel_encoder *encoder,
 			  struct drm_modeset_acquire_ctx *ctx);
 void intel_dp_link_check(struct intel_encoder *encoder);
+void intel_dp_check_link_state(struct intel_dp *intel_dp);
 void intel_dp_set_power(struct intel_dp *intel_dp, u8 mode);
 void intel_dp_configure_protocol_converter(struct intel_dp *intel_dp,
 					   const struct intel_crtc_state *crtc_state);