drm/i915: Markup paired operations on display power domains

The majority of runtime-pm operations are bounded and scoped within a
function; these are easy to verify that the wakeref are handled
correctly. We can employ the compiler to help us, and reduce the number
of wakerefs tracked when debugging, by passing around cookies provided
by the various rpm_get functions to their rpm_put counterpart. This
makes the pairing explicit, and given the required wakeref cookie the
compiler can verify that we pass an initialised value to the rpm_put
(quite handy for double checking error paths).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-16-chris@chris-wilson.co.uk

1 files changed, 22 insertions, 16 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index d3cd40e656fe..fc85fd77a661 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -621,8 +621,8 @@ static void pps_unlock(struct intel_dp *intel_dp)
 
 	mutex_unlock(&dev_priv->pps_mutex);
 
-	intel_display_power_put(dev_priv,
-				intel_aux_power_domain(dp_to_dig_port(intel_dp)));
+	intel_display_power_put_unchecked(dev_priv,
+					  intel_aux_power_domain(dp_to_dig_port(intel_dp)));
 }
 
 static void
@@ -2511,8 +2511,8 @@ static void edp_panel_vdd_off_sync(struct intel_dp *intel_dp)
 	if ((pp & PANEL_POWER_ON) == 0)
 		intel_dp->panel_power_off_time = ktime_get_boottime();
 
-	intel_display_power_put(dev_priv,
-				intel_aux_power_domain(intel_dig_port));
+	intel_display_power_put_unchecked(dev_priv,
+					  intel_aux_power_domain(intel_dig_port));
 }
 
 static void edp_panel_vdd_work(struct work_struct *__work)
@@ -2657,7 +2657,7 @@ static void edp_panel_off(struct intel_dp *intel_dp)
 	intel_dp->panel_power_off_time = ktime_get_boottime();
 
 	/* We got a reference when we enabled the VDD. */
-	intel_display_power_put(dev_priv, intel_aux_power_domain(dig_port));
+	intel_display_power_put_unchecked(dev_priv, intel_aux_power_domain(dig_port));
 }
 
 void intel_edp_panel_off(struct intel_dp *intel_dp)
@@ -2983,16 +2983,18 @@ static bool intel_dp_get_hw_state(struct intel_encoder *encoder,
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
+	intel_wakeref_t wakeref;
 	bool ret;
 
-	if (!intel_display_power_get_if_enabled(dev_priv,
-						encoder->power_domain))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     encoder->power_domain);
+	if (!wakeref)
 		return false;
 
 	ret = intel_dp_port_enabled(dev_priv, intel_dp->output_reg,
 				    encoder->port, pipe);
 
-	intel_display_power_put(dev_priv, encoder->power_domain);
+	intel_display_power_put(dev_priv, encoder->power_domain, wakeref);
 
 	return ret;
 }
@@ -5365,12 +5367,13 @@ intel_dp_detect(struct drm_connector *connector,
 	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));
 
-	intel_display_power_get(dev_priv, aux_domain);
+	wakeref = intel_display_power_get(dev_priv, aux_domain);
 
 	/* Can't disconnect eDP */
 	if (intel_dp_is_edp(intel_dp))
@@ -5436,7 +5439,7 @@ intel_dp_detect(struct drm_connector *connector,
 
 		ret = intel_dp_retrain_link(encoder, ctx);
 		if (ret) {
-			intel_display_power_put(dev_priv, aux_domain);
+			intel_display_power_put(dev_priv, aux_domain, wakeref);
 			return ret;
 		}
 	}
@@ -5460,7 +5463,7 @@ out:
 	if (status != connector_status_connected && !intel_dp->is_mst)
 		intel_dp_unset_edid(intel_dp);
 
-	intel_display_power_put(dev_priv, aux_domain);
+	intel_display_power_put(dev_priv, aux_domain, wakeref);
 	return status;
 }
 
@@ -5473,6 +5476,7 @@ intel_dp_force(struct drm_connector *connector)
 	struct drm_i915_private *dev_priv = to_i915(intel_encoder->base.dev);
 	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);
@@ -5481,11 +5485,11 @@ intel_dp_force(struct drm_connector *connector)
 	if (connector->status != connector_status_connected)
 		return;
 
-	intel_display_power_get(dev_priv, aux_domain);
+	wakeref = intel_display_power_get(dev_priv, aux_domain);
 
 	intel_dp_set_edid(intel_dp);
 
-	intel_display_power_put(dev_priv, aux_domain);
+	intel_display_power_put(dev_priv, aux_domain, wakeref);
 }
 
 static int intel_dp_get_modes(struct drm_connector *connector)
@@ -5931,6 +5935,7 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
 	struct intel_dp *intel_dp = &intel_dig_port->dp;
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
 	enum irqreturn ret = IRQ_NONE;
+	intel_wakeref_t wakeref;
 
 	if (long_hpd && intel_dig_port->base.type == INTEL_OUTPUT_EDP) {
 		/*
@@ -5953,8 +5958,8 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
 		return IRQ_NONE;
 	}
 
-	intel_display_power_get(dev_priv,
-				intel_aux_power_domain(intel_dig_port));
+	wakeref = intel_display_power_get(dev_priv,
+					  intel_aux_power_domain(intel_dig_port));
 
 	if (intel_dp->is_mst) {
 		if (intel_dp_check_mst_status(intel_dp) == -EINVAL) {
@@ -5984,7 +5989,8 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
 
 put_power:
 	intel_display_power_put(dev_priv,
-				intel_aux_power_domain(intel_dig_port));
+				intel_aux_power_domain(intel_dig_port),
+				wakeref);
 
 	return ret;
 }