[PATCH v2 07/11] drm/i915: Remove the unneeded AUX power ref from intel_dp_detect()

[Imre Deak]

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.

Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/intel_display.h    |  1 +
 drivers/gpu/drm/i915/intel_dp.c         | 32 +++++++++++++++++--------
 drivers/gpu/drm/i915/intel_runtime_pm.c |  4 ++++
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.h b/drivers/gpu/drm/i915/intel_display.h
index 1b6f5a71184d..7f3fafdfbd5f 100644
--- a/drivers/gpu/drm/i915/intel_display.h
+++ b/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,
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1e011998e9d5..24cca12a9a3e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -216,15 +216,21 @@ 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;
 
+	wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_DISPLAY_CORE);
+
 	lane_info = (I915_READ(PORT_TX_DFLEXDPSP) &
 		     DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
 		    DP_LANE_ASSIGNMENT_SHIFT(tc_port);
 
+	intel_display_power_put_async(dev_priv, POWER_DOMAIN_DISPLAY_CORE,
+				      wakeref);
+
 	switch (lane_info) {
 	default:
 		MISSING_CASE(lane_info);
@@ -5294,7 +5300,7 @@ 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 +5330,20 @@ 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 res;
+
+	wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_DISPLAY_CORE);
+	res = __intel_digital_port_connected(encoder);
+	intel_display_power_put_async(dev_priv, POWER_DOMAIN_DISPLAY_CORE,
+				      wakeref);
+
+	return res;
+}
+
 static struct edid *
 intel_dp_get_edid(struct intel_dp *intel_dp)
 {
@@ -5377,16 +5397,11 @@ 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 +5465,8 @@ 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 +5488,6 @@ 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;
 }
 
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 829d483d27e9..618dd42f1b2d 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -406,6 +406,8 @@ 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:
@@ -2383,6 +2385,7 @@ 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) |	\
@@ -2429,6 +2432,7 @@ 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) |		\
-- 
2.17.1