drm/i915: Add intel_digital_port lock/unlock hooks

Add hooks to intel_digital_port to lock and unlock the port and add a
helper to check the connector's detect status while the port is locked
already. This simplifies checking the connector detect status in
intel_dp_aux_xfer() and intel_digital_port_connected() in the next two
patches aborting AUX transfers on all DP connectors (except eDP) and
filtering HPD glitches.

Link: https://patchwork.freedesktop.org/patch/msgid/20240104083008.2715733-11-imre.deak@intel.com
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>

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

@@ -5117,6 +5117,9 @@ void intel_ddi_init(struct drm_i915_private *dev_priv,
 		encoder->suspend_complete = intel_ddi_tc_encoder_suspend_complete;
 		encoder->shutdown_complete = intel_ddi_tc_encoder_shutdown_complete;
 
+		dig_port->lock = intel_tc_port_lock;
+		dig_port->unlock = intel_tc_port_unlock;
+
 		if (intel_tc_port_init(dig_port, is_legacy) < 0)
 			goto err;
 	}

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

@@ -1890,6 +1890,9 @@ struct intel_digital_port {
 	u32 (*infoframes_enabled)(struct intel_encoder *encoder,
 				  const struct intel_crtc_state *pipe_config);
 	bool (*connected)(struct intel_encoder *encoder);
+
+	void (*lock)(struct intel_digital_port *dig_port);
+	void (*unlock)(struct intel_digital_port *dig_port);
 };
 
 struct intel_dp_mst_encoder {

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

@@ -5426,8 +5426,24 @@ edp_detect(struct intel_dp *intel_dp)
 	return connector_status_connected;
 }
 
+void intel_digital_port_lock(struct intel_encoder *encoder)
+{
+	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
+
+	if (dig_port->lock)
+		dig_port->lock(dig_port);
+}
+
+void intel_digital_port_unlock(struct intel_encoder *encoder)
+{
+	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
+
+	if (dig_port->unlock)
+		dig_port->unlock(dig_port);
+}
+
 /*
- * intel_digital_port_connected - is the specified port connected?
+ * intel_digital_port_connected_locked - is the specified port connected?
  * @encoder: intel_encoder
  *
  * In cases where there's a connector physically connected but it can't be used
@@ -5435,9 +5451,12 @@ edp_detect(struct intel_dp *intel_dp)
  * pretty much treat the port as disconnected. This is relevant for type-C
  * (starting on ICL) where there's ownership involved.
  *
+ * The caller must hold the lock acquired by calling intel_digital_port_lock()
+ * when calling this function.
+ *
  * Return %true if port is connected, %false otherwise.
  */
-bool intel_digital_port_connected(struct intel_encoder *encoder)
+bool intel_digital_port_connected_locked(struct intel_encoder *encoder)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
@@ -5450,6 +5469,17 @@ bool intel_digital_port_connected(struct intel_encoder *encoder)
 	return is_connected;
 }
 
+bool intel_digital_port_connected(struct intel_encoder *encoder)
+{
+	bool ret;
+
+	intel_digital_port_lock(encoder);
+	ret = intel_digital_port_connected_locked(encoder);
+	intel_digital_port_unlock(encoder);
+
+	return ret;
+}
+
 static const struct drm_edid *
 intel_dp_get_edid(struct intel_dp *intel_dp)
 {

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

@@ -115,7 +115,10 @@ void intel_dp_set_infoframes(struct intel_encoder *encoder, bool enable,
 void intel_read_dp_sdp(struct intel_encoder *encoder,
 		       struct intel_crtc_state *crtc_state,
 		       unsigned int type);
+void intel_digital_port_lock(struct intel_encoder *encoder);
+void intel_digital_port_unlock(struct intel_encoder *encoder);
 bool intel_digital_port_connected(struct intel_encoder *encoder);
+bool intel_digital_port_connected_locked(struct intel_encoder *encoder);
 int intel_dp_dsc_compute_max_bpp(const struct intel_connector *connector,
 				 u8 dsc_max_bpc);
 u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,

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

@@ -9,6 +9,7 @@
 #include "intel_bios.h"
 #include "intel_de.h"
 #include "intel_display_types.h"
+#include "intel_dp.h"
 #include "intel_dp_aux.h"
 #include "intel_dp_aux_regs.h"
 #include "intel_pps.h"
@@ -228,6 +229,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
 		  u32 aux_send_ctl_flags)
 {
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct intel_encoder *encoder = &dig_port->base;
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
 	enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
 	bool is_tc_port = intel_phy_is_tc(i915, phy);
@@ -245,18 +247,17 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
 	for (i = 0; i < ARRAY_SIZE(ch_data); i++)
 		ch_data[i] = intel_dp->aux_ch_data_reg(intel_dp, i);
 
-	if (is_tc_port) {
-		intel_tc_port_lock(dig_port);
-		/*
-		 * Abort transfers on a disconnected port as required by
-		 * DP 1.4a link CTS 4.2.1.5, also avoiding the long AUX
-		 * timeouts that would otherwise happen.
-		 * TODO: abort the transfer on non-TC ports as well.
-		 */
-		if (!intel_tc_port_connected_locked(&dig_port->base)) {
-			ret = -ENXIO;
-			goto out_unlock;
-		}
+	intel_digital_port_lock(encoder);
+	/*
+	 * Abort transfers on a disconnected port as required by
+	 * DP 1.4a link CTS 4.2.1.5, also avoiding the long AUX
+	 * timeouts that would otherwise happen.
+	 * TODO: abort the transfer on non-TC ports as well.
+	 */
+	if (is_tc_port &&
+	    !intel_digital_port_connected_locked(&dig_port->base)) {
+		ret = -ENXIO;
+		goto out_unlock;
 	}
 
 	aux_domain = intel_aux_power_domain(dig_port);
@@ -423,8 +424,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
 	intel_pps_unlock(intel_dp, pps_wakeref);
 	intel_display_power_put_async(i915, aux_domain, aux_wakeref);
 out_unlock:
-	if (is_tc_port)
-		intel_tc_port_unlock(dig_port);
+	intel_digital_port_unlock(encoder);
 
 	return ret;
 }

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

@@ -1590,7 +1590,7 @@ void intel_tc_port_sanitize_mode(struct intel_digital_port *dig_port,
  * connected ports are usable, and avoids exposing to the users objects they
  * can't really use.
  */
-bool intel_tc_port_connected_locked(struct intel_encoder *encoder)
+bool intel_tc_port_connected(struct intel_encoder *encoder)
 {
 	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
@@ -1605,19 +1605,6 @@ bool intel_tc_port_connected_locked(struct intel_encoder *encoder)
 	return tc_phy_hpd_live_status(tc) & mask;
 }
 
-bool intel_tc_port_connected(struct intel_encoder *encoder)
-{
-	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
-	struct intel_tc_port *tc = to_tc_port(dig_port);
-	bool is_connected;
-
-	mutex_lock(&tc->lock);
-	is_connected = intel_tc_port_connected_locked(encoder);
-	mutex_unlock(&tc->lock);
-
-	return is_connected;
-}
-
 static bool __intel_tc_port_link_needs_reset(struct intel_tc_port *tc)
 {
 	bool ret;

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

@@ -17,7 +17,6 @@ bool intel_tc_port_in_dp_alt_mode(struct intel_digital_port *dig_port);
 bool intel_tc_port_in_legacy_mode(struct intel_digital_port *dig_port);
 
 bool intel_tc_port_connected(struct intel_encoder *encoder);
-bool intel_tc_port_connected_locked(struct intel_encoder *encoder);
 
 u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port);
 int intel_tc_port_max_lane_count(struct intel_digital_port *dig_port);