[PATCH v2 04/21] drm/i915/dp: Add support to notify MST connectors to retry modesets

[Imre Deak <imre.deak@intel.com>]

On shared (Thunderbolt) links with DP tunnels, the modeset may need to
be retried on all connectors on the link due to a link BW limitation
arising only after the atomic check phase. To support this add a helper
function queuing a work to retry the modeset on a given port's connector
and at the same time any MST connector with streams through the same
port. A follow-up change enabling the DP tunnel Bandwidth Allocation
Mode will take this into use.

v2:
- Send the uevent only to enabled MST connectors. (Jouni)

Cc: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c  |  5 ++-
 drivers/gpu/drm/i915/display/intel_dp.c       | 45 ++++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_dp.h       |  6 +++
 .../drm/i915/display/intel_dp_link_training.c |  3 +-
 drivers/gpu/drm/i915/display/intel_dp_mst.c   |  2 +
 5 files changed, 55 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 485c38d71f106..2ee26d19c200b 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -8085,8 +8085,9 @@ void intel_hpd_poll_fini(struct drm_i915_private *i915)
 	/* Kill all the work that may have been queued by hpd. */
 	drm_connector_list_iter_begin(&i915->drm, &conn_iter);
 	for_each_intel_connector_iter(connector, &conn_iter) {
-		if (connector->modeset_retry_work.func)
-			cancel_work_sync(&connector->modeset_retry_work);
+		if (connector->modeset_retry_work.func &&
+		    cancel_work_sync(&connector->modeset_retry_work))
+			drm_connector_put(&connector->base);
 		if (connector->hdcp.shim) {
 			cancel_delayed_work_sync(&connector->hdcp.check_work);
 			cancel_work_sync(&connector->hdcp.prop_work);
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 217196196e50a..88606e336a920 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2842,6 +2842,40 @@ intel_dp_audio_compute_config(struct intel_encoder *encoder,
 					intel_dp_is_uhbr(pipe_config);
 }
 
+void intel_dp_queue_modeset_retry_work(struct intel_connector *connector)
+{
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
+
+	drm_connector_get(&connector->base);
+	if (!queue_work(i915->unordered_wq, &connector->modeset_retry_work))
+		drm_connector_put(&connector->base);
+}
+
+void
+intel_dp_queue_modeset_retry_for_link(struct intel_atomic_state *state,
+				      struct intel_encoder *encoder,
+				      const struct intel_crtc_state *crtc_state)
+{
+	struct intel_connector *connector;
+	struct intel_digital_connector_state *conn_state;
+	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+	int i;
+
+	if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST)) {
+		intel_dp_queue_modeset_retry_work(intel_dp->attached_connector);
+
+		return;
+	}
+
+	for_each_new_intel_connector_in_state(state, connector, conn_state, i) {
+		if (!conn_state->base.crtc)
+			continue;
+
+		if (connector->mst_port == intel_dp)
+			intel_dp_queue_modeset_retry_work(connector);
+	}
+}
+
 int
 intel_dp_compute_config(struct intel_encoder *encoder,
 			struct intel_crtc_state *pipe_config,
@@ -6441,6 +6475,14 @@ static void intel_dp_modeset_retry_work_fn(struct work_struct *work)
 	mutex_unlock(&connector->dev->mode_config.mutex);
 	/* Send Hotplug uevent so userspace can reprobe */
 	drm_kms_helper_connector_hotplug_event(connector);
+
+	drm_connector_put(connector);
+}
+
+void intel_dp_init_modeset_retry_work(struct intel_connector *connector)
+{
+	INIT_WORK(&connector->modeset_retry_work,
+		  intel_dp_modeset_retry_work_fn);
 }
 
 bool
@@ -6457,8 +6499,7 @@ intel_dp_init_connector(struct intel_digital_port *dig_port,
 	int type;
 
 	/* Initialize the work for modeset in case of link train failure */
-	INIT_WORK(&intel_connector->modeset_retry_work,
-		  intel_dp_modeset_retry_work_fn);
+	intel_dp_init_modeset_retry_work(intel_connector);
 
 	if (drm_WARN(dev, dig_port->max_lanes < 1,
 		     "Not enough lanes (%d) for DP on [ENCODER:%d:%s]\n",
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index 530cc97bc42f4..e2875e03afba0 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -43,6 +43,12 @@ void intel_dp_adjust_compliance_config(struct intel_dp *intel_dp,
 bool intel_dp_limited_color_range(const struct intel_crtc_state *crtc_state,
 				  const struct drm_connector_state *conn_state);
 int intel_dp_min_bpp(enum intel_output_format output_format);
+void intel_dp_init_modeset_retry_work(struct intel_connector *connector);
+void intel_dp_queue_modeset_retry_work(struct intel_connector *connector);
+void
+intel_dp_queue_modeset_retry_for_link(struct intel_atomic_state *state,
+				      struct intel_encoder *encoder,
+				      const struct intel_crtc_state *crtc_state);
 bool intel_dp_init_connector(struct intel_digital_port *dig_port,
 			     struct intel_connector *intel_connector);
 void intel_dp_set_link_params(struct intel_dp *intel_dp,
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
index 1abfafbbfa757..7b140cbf8dd31 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -1075,7 +1075,6 @@ static void intel_dp_schedule_fallback_link_training(struct intel_dp *intel_dp,
 						     const struct intel_crtc_state *crtc_state)
 {
 	struct intel_connector *intel_connector = intel_dp->attached_connector;
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
 
 	if (!intel_digital_port_connected(&dp_to_dig_port(intel_dp)->base)) {
 		lt_dbg(intel_dp, DP_PHY_DPRX, "Link Training failed on disconnected sink.\n");
@@ -1093,7 +1092,7 @@ static void intel_dp_schedule_fallback_link_training(struct intel_dp *intel_dp,
 	}
 
 	/* Schedule a Hotplug Uevent to userspace to start modeset */
-	queue_work(i915->unordered_wq, &intel_connector->modeset_retry_work);
+	intel_dp_queue_modeset_retry_work(intel_connector);
 }
 
 /* Perform the link training on all LTTPRs and the DPRX on a link. */
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 5307ddd4edcf5..c685b64bb7810 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -1546,6 +1546,8 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
 	intel_connector->port = port;
 	drm_dp_mst_get_port_malloc(port);
 
+	intel_dp_init_modeset_retry_work(intel_connector);
+
 	intel_connector->dp.dsc_decompression_aux = drm_dp_mst_dsc_aux_for_port(port);
 	intel_dp_mst_read_decompression_port_dsc_caps(intel_dp, intel_connector);
 	intel_connector->dp.dsc_hblank_expansion_quirk =
-- 
2.39.2