drm/i915: Add reverse mapping between port and intel_encoder

This patch adds a reverse mapping from a digital port number to
intel_encoder object containing the corresponding intel_digital_port.
It simplifies the query of the encoder a lot.

Note that, even if it's a valid digital port, the dig_port_map[] might
point still to NULL -- usually it implies a DP MST port.  Due to this
fact, the NULL check in each place has no WARN_ON() and just skips the
port.  Once when the situation changes in future, we might introduce
WARN_ON() for a more strict check.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

drivers/gpu/drm/i915/i915_drv.h

@@ -1944,6 +1944,8 @@ struct drm_i915_private {
 	/* perform PHY state sanity checks? */
 	bool chv_phy_assert[2];
 
+	struct intel_encoder *dig_port_map[I915_MAX_PORTS];
+
 	/*
 	 * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
 	 * will be rejected. Instead look for a better place.

drivers/gpu/drm/i915/intel_audio.c

@@ -636,15 +636,14 @@ static int i915_audio_component_sync_audio_rate(struct device *dev,
 						int port, int rate)
 {
 	struct drm_i915_private *dev_priv = dev_to_i915(dev);
-	struct drm_device *drm_dev = dev_priv->dev;
 	struct intel_encoder *intel_encoder;
-	struct intel_digital_port *intel_dig_port;
 	struct intel_crtc *crtc;
 	struct drm_display_mode *mode;
 	struct i915_audio_component *acomp = dev_priv->audio_component;
-	enum pipe pipe = -1;
+	enum pipe pipe = INVALID_PIPE;
 	u32 tmp;
 	int n;
+	int err = 0;
 
 	/* HSW, BDW, SKL, KBL need this fix */
 	if (!IS_SKYLAKE(dev_priv) &&
@@ -655,26 +654,22 @@ static int i915_audio_component_sync_audio_rate(struct device *dev,
 
 	mutex_lock(&dev_priv->av_mutex);
 	/* 1. get the pipe */
-	for_each_intel_encoder(drm_dev, intel_encoder) {
-		if (intel_encoder->type != INTEL_OUTPUT_HDMI)
-			continue;
-		intel_dig_port = enc_to_dig_port(&intel_encoder->base);
-		if (port == intel_dig_port->port) {
-			crtc = to_intel_crtc(intel_encoder->base.crtc);
-			if (!crtc) {
-				DRM_DEBUG_KMS("%s: crtc is NULL\n", __func__);
-				continue;
+	intel_encoder = dev_priv->dig_port_map[port];
+	/* intel_encoder might be NULL for DP MST */
+	if (!intel_encoder || !intel_encoder->base.crtc ||
+	    intel_encoder->type != INTEL_OUTPUT_HDMI) {
+		DRM_DEBUG_KMS("no valid port %c\n", port_name(port));
+		err = -ENODEV;
+		goto unlock;
 	}
+	crtc = to_intel_crtc(intel_encoder->base.crtc);
 	pipe = crtc->pipe;
-			break;
-		}
-	}
-
 	if (pipe == INVALID_PIPE) {
 		DRM_DEBUG_KMS("no pipe for the port %c\n", port_name(port));
-		mutex_unlock(&dev_priv->av_mutex);
-		return -ENODEV;
+		err = -ENODEV;
+		goto unlock;
 	}
+
 	DRM_DEBUG_KMS("pipe %c connects port %c\n",
 				  pipe_name(pipe), port_name(port));
 	mode = &crtc->config->base.adjusted_mode;
@@ -687,8 +682,7 @@ static int i915_audio_component_sync_audio_rate(struct device *dev,
 		tmp = I915_READ(HSW_AUD_CFG(pipe));
 		tmp &= ~AUD_CONFIG_N_PROG_ENABLE;
 		I915_WRITE(HSW_AUD_CFG(pipe), tmp);
-		mutex_unlock(&dev_priv->av_mutex);
-		return 0;
+		goto unlock;
 	}
 
 	n = audio_config_get_n(mode, rate);
@@ -698,8 +692,7 @@ static int i915_audio_component_sync_audio_rate(struct device *dev,
 		tmp = I915_READ(HSW_AUD_CFG(pipe));
 		tmp &= ~AUD_CONFIG_N_PROG_ENABLE;
 		I915_WRITE(HSW_AUD_CFG(pipe), tmp);
-		mutex_unlock(&dev_priv->av_mutex);
-		return 0;
+		goto unlock;
 	}
 
 	/* 3. set the N/CTS/M */
@@ -707,8 +700,9 @@ static int i915_audio_component_sync_audio_rate(struct device *dev,
 	tmp = audio_config_setup_n_reg(n, tmp);
 	I915_WRITE(HSW_AUD_CFG(pipe), tmp);
 
+ unlock:
 	mutex_unlock(&dev_priv->av_mutex);
-	return 0;
+	return err;
 }
 
 static int i915_audio_component_get_eld(struct device *dev, int port,
@@ -716,27 +710,22 @@ static int i915_audio_component_get_eld(struct device *dev, int port,
 					unsigned char *buf, int max_bytes)
 {
 	struct drm_i915_private *dev_priv = dev_to_i915(dev);
-	struct drm_device *drm_dev = dev_priv->dev;
 	struct intel_encoder *intel_encoder;
 	struct intel_digital_port *intel_dig_port;
 	const u8 *eld;
 	int ret = -EINVAL;
 
 	mutex_lock(&dev_priv->av_mutex);
-	for_each_intel_encoder(drm_dev, intel_encoder) {
-		if (intel_encoder->type != INTEL_OUTPUT_DISPLAYPORT &&
-		    intel_encoder->type != INTEL_OUTPUT_HDMI)
-			continue;
-		intel_dig_port = enc_to_dig_port(&intel_encoder->base);
-		if (port == intel_dig_port->port) {
+	intel_encoder = dev_priv->dig_port_map[port];
+	/* intel_encoder might be NULL for DP MST */
+	if (intel_encoder) {
 		ret = 0;
+		intel_dig_port = enc_to_dig_port(&intel_encoder->base);
 		*enabled = intel_dig_port->audio_connector != NULL;
-			if (!*enabled)
-				break;
+		if (*enabled) {
 			eld = intel_dig_port->audio_connector->eld;
 			ret = drm_eld_size(eld);
 			memcpy(buf, eld, min(max_bytes, ret));
-			break;
 		}
 	}
 

drivers/gpu/drm/i915/intel_ddi.c

@@ -3295,6 +3295,7 @@ void intel_ddi_init(struct drm_device *dev, enum port port)
 	intel_encoder->get_config = intel_ddi_get_config;
 
 	intel_dig_port->port = port;
+	dev_priv->dig_port_map[port] = intel_encoder;
 	intel_dig_port->saved_port_bits = I915_READ(DDI_BUF_CTL(port)) &
 					  (DDI_BUF_PORT_REVERSAL |
 					   DDI_A_4_LANES);

drivers/gpu/drm/i915/intel_dp.c

@@ -6003,6 +6003,7 @@ intel_dp_init(struct drm_device *dev,
 	}
 
 	intel_dig_port->port = port;
+	dev_priv->dig_port_map[port] = intel_encoder;
 	intel_dig_port->dp.output_reg = output_reg;
 
 	intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;

drivers/gpu/drm/i915/intel_hdmi.c

@@ -2148,6 +2148,7 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 void intel_hdmi_init(struct drm_device *dev,
 		     i915_reg_t hdmi_reg, enum port port)
 {
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_digital_port *intel_dig_port;
 	struct intel_encoder *intel_encoder;
 	struct intel_connector *intel_connector;
@@ -2216,6 +2217,7 @@ void intel_hdmi_init(struct drm_device *dev,
 		intel_encoder->cloneable |= 1 << INTEL_OUTPUT_HDMI;
 
 	intel_dig_port->port = port;
+	dev_priv->dig_port_map[port] = intel_encoder;
 	intel_dig_port->hdmi.hdmi_reg = hdmi_reg;
 	intel_dig_port->dp.output_reg = INVALID_MMIO_REG;