drm/i915: Init lspcon after HPD in intel_dp_detect()

On HP 800 G4 DM, if HDMI cable isn't plugged before boot, the HDMI port
becomes useless and never responds to cable hotplugging:
[    3.031904] [drm:lspcon_init [i915]] *ERROR* Failed to probe lspcon
[    3.031945] [drm:intel_ddi_init [i915]] *ERROR* LSPCON init failed on port D

Seems like the lspcon chip on the system only gets powered after the
cable is plugged.

Consilidate lspcon_init() into lspcon_resume() to dynamically init
lspcon chip, and make HDMI port work.

v6:
 - Rebase on latest for-linux-next.
v5:
 - Consolidate lspcon_resume() with lspcon_init().
 - Move more logic into lspcon code.
v4:
 - Trust VBT in intel_infoframe_init().
 - Init lspcon in intel_dp_detect().
v3:
 - Make sure it's handled under long HPD case.
v2:
 - Move lspcon_init() inside of intel_dp_hpd_pulse().

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/203Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200610075542.12882-1-kai.heng.feng@canonical.com

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

@@ -5111,7 +5111,7 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 {
 	struct intel_digital_port *dig_port;
 	struct intel_encoder *encoder;
-	bool init_hdmi, init_dp, init_lspcon = false;
+	bool init_hdmi, init_dp;
 	enum phy phy = intel_port_to_phy(dev_priv, port);
 
 	/*
@@ -5137,7 +5137,6 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 		 * is initialized before lspcon.
 		 */
 		init_dp = true;
-		init_lspcon = true;
 		init_hdmi = false;
 		drm_dbg_kms(&dev_priv->drm, "VBT says port %c has lspcon\n",
 			    port_name(port));
@@ -5238,22 +5237,6 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 			goto err;
 	}
 
-	if (init_lspcon) {
-		if (lspcon_init(dig_port))
-			/* TODO: handle hdmi info frame part */
-			drm_dbg_kms(&dev_priv->drm,
-				    "LSPCON init success on port %c\n",
-				    port_name(port));
-		else
-			/*
-			 * LSPCON init faied, but DP init was success, so
-			 * lets try to drive as DP++ port.
-			 */
-			drm_err(&dev_priv->drm,
-				"LSPCON init failed on port %c\n",
-				port_name(port));
-	}
-
 	if (INTEL_GEN(dev_priv) >= 11) {
 		if (intel_phy_is_tc(dev_priv, phy))
 			dig_port->connected = intel_tc_port_connected;

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

@@ -6173,15 +6173,14 @@ static enum drm_connector_status
 intel_dp_detect_dpcd(struct intel_dp *intel_dp)
 {
 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
-	struct intel_lspcon *lspcon = dp_to_lspcon(intel_dp);
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 	u8 *dpcd = intel_dp->dpcd;
 	u8 type;
 
 	if (drm_WARN_ON(&i915->drm, intel_dp_is_edp(intel_dp)))
 		return connector_status_connected;
 
-	if (lspcon->active)
-		lspcon_resume(lspcon);
+	lspcon_resume(dig_port);
 
 	if (!intel_dp_get_dpcd(intel_dp))
 		return connector_status_disconnected;
@@ -6765,14 +6764,13 @@ void intel_dp_encoder_reset(struct drm_encoder *encoder)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->dev);
 	struct intel_dp *intel_dp = enc_to_intel_dp(to_intel_encoder(encoder));
-	struct intel_lspcon *lspcon = dp_to_lspcon(intel_dp);
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 	intel_wakeref_t wakeref;
 
 	if (!HAS_DDI(dev_priv))
 		intel_dp->DP = intel_de_read(dev_priv, intel_dp->output_reg);
 
-	if (lspcon->active)
-		lspcon_resume(lspcon);
+	lspcon_resume(dig_port);
 
 	intel_dp->reset_link_params = true;
 

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

@@ -3215,7 +3215,7 @@ void intel_infoframe_init(struct intel_digital_port *dig_port)
 		dig_port->set_infoframes = g4x_set_infoframes;
 		dig_port->infoframes_enabled = g4x_infoframes_enabled;
 	} else if (HAS_DDI(dev_priv)) {
-		if (dig_port->lspcon.active) {
+		if (intel_bios_is_lspcon_present(dev_priv, dig_port->base.port)) {
 			dig_port->write_infoframe = lspcon_write_infoframe;
 			dig_port->read_infoframe = lspcon_read_infoframe;
 			dig_port->set_infoframes = lspcon_set_infoframes;

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

@@ -525,26 +525,6 @@ u32 lspcon_infoframes_enabled(struct intel_encoder *encoder,
 	return 0;
 }
 
-void lspcon_resume(struct intel_lspcon *lspcon)
-{
-	enum drm_lspcon_mode expected_mode;
-
-	if (lspcon_wake_native_aux_ch(lspcon)) {
-		expected_mode = DRM_LSPCON_MODE_PCON;
-		lspcon_resume_in_pcon_wa(lspcon);
-	} else {
-		expected_mode = DRM_LSPCON_MODE_LS;
-	}
-
-	if (lspcon_wait_mode(lspcon, expected_mode) == DRM_LSPCON_MODE_PCON)
-		return;
-
-	if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON))
-		DRM_ERROR("LSPCON resume failed\n");
-	else
-		DRM_DEBUG_KMS("LSPCON resume success\n");
-}
-
 void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon)
 {
 	lspcon_wait_mode(lspcon, DRM_LSPCON_MODE_PCON);
@@ -554,15 +534,8 @@ bool lspcon_init(struct intel_digital_port *dig_port)
 {
 	struct intel_dp *dp = &dig_port->dp;
 	struct intel_lspcon *lspcon = &dig_port->lspcon;
-	struct drm_device *dev = dig_port->base.base.dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct drm_connector *connector = &dp->attached_connector->base;
 
-	if (!HAS_LSPCON(dev_priv)) {
-		DRM_ERROR("LSPCON is not supported on this platform\n");
-		return false;
-	}
-
 	lspcon->active = false;
 	lspcon->mode = DRM_LSPCON_MODE_INVALID;
 
@@ -586,3 +559,37 @@ bool lspcon_init(struct intel_digital_port *dig_port)
 	DRM_DEBUG_KMS("Success: LSPCON init\n");
 	return true;
 }
+
+void lspcon_resume(struct intel_digital_port *dig_port)
+{
+	struct intel_lspcon *lspcon = &dig_port->lspcon;
+	struct drm_device *dev = dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	enum drm_lspcon_mode expected_mode;
+
+	if (!intel_bios_is_lspcon_present(dev_priv, dig_port->base.port))
+		return;
+
+	if (!lspcon->active) {
+		if (!lspcon_init(dig_port)) {
+			DRM_ERROR("LSPCON init failed on port %c\n",
+				  port_name(dig_port->base.port));
+			return;
+		}
+	}
+
+	if (lspcon_wake_native_aux_ch(lspcon)) {
+		expected_mode = DRM_LSPCON_MODE_PCON;
+		lspcon_resume_in_pcon_wa(lspcon);
+	} else {
+		expected_mode = DRM_LSPCON_MODE_LS;
+	}
+
+	if (lspcon_wait_mode(lspcon, expected_mode) == DRM_LSPCON_MODE_PCON)
+		return;
+
+	if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON))
+		DRM_ERROR("LSPCON resume failed\n");
+	else
+		DRM_DEBUG_KMS("LSPCON resume success\n");
+}

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

@@ -15,8 +15,7 @@ struct intel_digital_port;
 struct intel_encoder;
 struct intel_lspcon;
 
-bool lspcon_init(struct intel_digital_port *dig_port);
-void lspcon_resume(struct intel_lspcon *lspcon);
+void lspcon_resume(struct intel_digital_port *dig_port);
 void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon);
 void lspcon_write_infoframe(struct intel_encoder *encoder,
 			    const struct intel_crtc_state *crtc_state,