drm/i915: Remove the unneeded AUX power ref from intel_dp_detect()

We don't need the AUX power for the whole duration of the detect, only
when we're doing AUX transfers. The AUX transfer function takes its own
reference on the AUX power domain already. The two places during detect
which access display core registers (not specific to a
pipe/port/transcoder) only need the power domain that is required for
that access. That power domain is equivalent to the device global power
domain on most platforms (enabled whenever we hold a runtime PM
reference) except on CHV/VLV where it's equivalent to the display power
well.

Add a new power domain that reflects the above, and use this at the two
spots accessing registers. With that we can avoid taking the AUX
reference for the whole duration of the detect function.

Put the domains asynchronously to avoid the unneeded on-off-on toggling.

Also adapt the idea from with_intel_runtime_pm et al. for making it easy
to write short sequences where a display power ref is needed.

v2: (Ville)
- Add with_intel_display_power() helper to simplify things.
- s/bool res/bool is_connected/

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190509173446.31095-8-imre.deak@intel.com

drivers/gpu/drm/i915/intel_display.h

@@ -220,6 +220,7 @@ enum aux_ch {
 #define aux_ch_name(a) ((a) + 'A')
 
 enum intel_display_power_domain {
+	POWER_DOMAIN_DISPLAY_CORE,
 	POWER_DOMAIN_PIPE_A,
 	POWER_DOMAIN_PIPE_B,
 	POWER_DOMAIN_PIPE_C,

drivers/gpu/drm/i915/intel_dp.c

@@ -216,14 +216,16 @@ static int intel_dp_get_fia_supported_lane_count(struct intel_dp *intel_dp)
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
 	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
+	intel_wakeref_t wakeref;
 	u32 lane_info;
 
 	if (tc_port == PORT_TC_NONE || dig_port->tc_type != TC_PORT_TYPEC)
 		return 4;
 
-	lane_info = (I915_READ(PORT_TX_DFLEXDPSP) &
-		     DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
-		    DP_LANE_ASSIGNMENT_SHIFT(tc_port);
+	with_intel_display_power(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref)
+		lane_info = (I915_READ(PORT_TX_DFLEXDPSP) &
+			     DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
+				DP_LANE_ASSIGNMENT_SHIFT(tc_port);
 
 	switch (lane_info) {
 	default:
@@ -5294,7 +5296,7 @@ static bool icl_digital_port_connected(struct intel_encoder *encoder)
  *
  * Return %true if port is connected, %false otherwise.
  */
-bool intel_digital_port_connected(struct intel_encoder *encoder)
+static bool __intel_digital_port_connected(struct intel_encoder *encoder)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 
@@ -5324,6 +5326,18 @@ bool intel_digital_port_connected(struct intel_encoder *encoder)
 	return false;
 }
 
+bool intel_digital_port_connected(struct intel_encoder *encoder)
+{
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	intel_wakeref_t wakeref;
+	bool is_connected;
+
+	with_intel_display_power(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref)
+		is_connected = __intel_digital_port_connected(encoder);
+
+	return is_connected;
+}
+
 static struct edid *
 intel_dp_get_edid(struct intel_dp *intel_dp)
 {
@@ -5377,16 +5391,11 @@ intel_dp_detect(struct drm_connector *connector,
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 	struct intel_encoder *encoder = &dig_port->base;
 	enum drm_connector_status status;
-	enum intel_display_power_domain aux_domain =
-		intel_aux_power_domain(dig_port);
-	intel_wakeref_t wakeref;
 
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
 		      connector->base.id, connector->name);
 	WARN_ON(!drm_modeset_is_locked(&dev_priv->drm.mode_config.connection_mutex));
 
-	wakeref = intel_display_power_get(dev_priv, aux_domain);
-
 	/* Can't disconnect eDP */
 	if (intel_dp_is_edp(intel_dp))
 		status = edp_detect(intel_dp);
@@ -5450,10 +5459,8 @@ intel_dp_detect(struct drm_connector *connector,
 		int ret;
 
 		ret = intel_dp_retrain_link(encoder, ctx);
-		if (ret) {
-			intel_display_power_put(dev_priv, aux_domain, wakeref);
+		if (ret)
 			return ret;
-		}
 	}
 
 	/*
@@ -5475,7 +5482,6 @@ intel_dp_detect(struct drm_connector *connector,
 	if (status != connector_status_connected && !intel_dp->is_mst)
 		intel_dp_unset_edid(intel_dp);
 
-	intel_display_power_put(dev_priv, aux_domain, wakeref);
 	return status;
 }
 

drivers/gpu/drm/i915/intel_runtime_pm.c

@@ -409,6 +409,8 @@ const char *
 intel_display_power_domain_str(enum intel_display_power_domain domain)
 {
 	switch (domain) {
+	case POWER_DOMAIN_DISPLAY_CORE:
+		return "DISPLAY_CORE";
 	case POWER_DOMAIN_PIPE_A:
 		return "PIPE_A";
 	case POWER_DOMAIN_PIPE_B:
@@ -2387,6 +2389,7 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 	BIT_ULL(POWER_DOMAIN_INIT))
 
 #define VLV_DISPLAY_POWER_DOMAINS (		\
+	BIT_ULL(POWER_DOMAIN_DISPLAY_CORE) |	\
 	BIT_ULL(POWER_DOMAIN_PIPE_A) |		\
 	BIT_ULL(POWER_DOMAIN_PIPE_B) |		\
 	BIT_ULL(POWER_DOMAIN_PIPE_A_PANEL_FITTER) |	\
@@ -2433,6 +2436,7 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 	BIT_ULL(POWER_DOMAIN_INIT))
 
 #define CHV_DISPLAY_POWER_DOMAINS (		\
+	BIT_ULL(POWER_DOMAIN_DISPLAY_CORE) |	\
 	BIT_ULL(POWER_DOMAIN_PIPE_A) |		\
 	BIT_ULL(POWER_DOMAIN_PIPE_B) |		\
 	BIT_ULL(POWER_DOMAIN_PIPE_C) |		\

drivers/gpu/drm/i915/intel_runtime_pm.h

@@ -91,6 +91,11 @@ intel_display_power_put_async(struct drm_i915_private *i915,
 	__intel_display_power_put_async(i915, domain, -1);
 }
 #endif
+
+#define with_intel_display_power(i915, domain, wf) \
+	for ((wf) = intel_display_power_get((i915), (domain)); (wf); \
+	     intel_display_power_put_async((i915), (domain), (wf)), (wf) = 0)
+
 void icl_dbuf_slices_update(struct drm_i915_private *dev_priv,
 			    u8 req_slices);