drm/i915: Track the temporary wakerefs used for hsw_get_pipe_config

Haswell+ require many power wells to probe the current HW display state.
Under the wakeref tracking scheme, we want each owner to store and
release the wakeref they use, so we can identify callers that have
leaked their wakeref. For hsw_get_pipe_config, this means we have to
keep the array of all wakerefs as it current acquires its power wells
piecemeal and releases them en masse.

By tracking these wakerefs, we should be able to eliminate a lot of
noise from the runtime-pm debug logs.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190406080341.2654-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/intel_display.c

@@ -9754,7 +9754,8 @@ static void haswell_get_ddi_pll(struct drm_i915_private *dev_priv,
 
 static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
 				     struct intel_crtc_state *pipe_config,
-				     u64 *power_domain_mask)
+				     u64 *power_domain_mask,
+				     intel_wakeref_t *wakerefs)
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -9762,6 +9763,7 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
 	unsigned long panel_transcoder_mask = 0;
 	unsigned long enabled_panel_transcoders = 0;
 	enum transcoder panel_transcoder;
+	intel_wakeref_t wf;
 	u32 tmp;
 
 	if (INTEL_GEN(dev_priv) >= 11)
@@ -9827,10 +9829,13 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
 		enabled_panel_transcoders != BIT(TRANSCODER_EDP));
 
 	power_domain = POWER_DOMAIN_TRANSCODER(pipe_config->cpu_transcoder);
-	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
+	WARN_ON(*power_domain_mask & BIT_ULL(power_domain));
+
+	wf = intel_display_power_get_if_enabled(dev_priv, power_domain);
+	if (!wf)
 		return false;
 
-	WARN_ON(*power_domain_mask & BIT_ULL(power_domain));
+	wakerefs[power_domain] = wf;
 	*power_domain_mask |= BIT_ULL(power_domain);
 
 	tmp = I915_READ(PIPECONF(pipe_config->cpu_transcoder));
@@ -9840,13 +9845,15 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
 
 static bool bxt_get_dsi_transcoder_state(struct intel_crtc *crtc,
 					 struct intel_crtc_state *pipe_config,
-					 u64 *power_domain_mask)
+					 u64 *power_domain_mask,
+					 intel_wakeref_t *wakerefs)
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	enum intel_display_power_domain power_domain;
-	enum port port;
 	enum transcoder cpu_transcoder;
+	intel_wakeref_t wf;
+	enum port port;
 	u32 tmp;
 
 	for_each_port_masked(port, BIT(PORT_A) | BIT(PORT_C)) {
@@ -9856,10 +9863,13 @@ static bool bxt_get_dsi_transcoder_state(struct intel_crtc *crtc,
 			cpu_transcoder = TRANSCODER_DSI_C;
 
 		power_domain = POWER_DOMAIN_TRANSCODER(cpu_transcoder);
-		if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
+		WARN_ON(*power_domain_mask & BIT_ULL(power_domain));
+
+		wf = intel_display_power_get_if_enabled(dev_priv, power_domain);
+		if (!wf)
 			continue;
 
-		WARN_ON(*power_domain_mask & BIT_ULL(power_domain));
+		wakerefs[power_domain] = wf;
 		*power_domain_mask |= BIT_ULL(power_domain);
 
 		/*
@@ -9938,6 +9948,7 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 				    struct intel_crtc_state *pipe_config)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	intel_wakeref_t wakerefs[POWER_DOMAIN_NUM], wf;
 	enum intel_display_power_domain power_domain;
 	u64 power_domain_mask;
 	bool active;
@@ -9945,16 +9956,21 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 	intel_crtc_init_scalers(crtc, pipe_config);
 
 	power_domain = POWER_DOMAIN_PIPE(crtc->pipe);
-	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
+	wf = intel_display_power_get_if_enabled(dev_priv, power_domain);
+	if (!wf)
 		return false;
+
+	wakerefs[power_domain] = wf;
 	power_domain_mask = BIT_ULL(power_domain);
 
 	pipe_config->shared_dpll = NULL;
 
-	active = hsw_get_transcoder_state(crtc, pipe_config, &power_domain_mask);
+	active = hsw_get_transcoder_state(crtc, pipe_config,
+					  &power_domain_mask, wakerefs);
 
 	if (IS_GEN9_LP(dev_priv) &&
-	    bxt_get_dsi_transcoder_state(crtc, pipe_config, &power_domain_mask)) {
+	    bxt_get_dsi_transcoder_state(crtc, pipe_config,
+					 &power_domain_mask, wakerefs)) {
 		WARN_ON(active);
 		active = true;
 	}
@@ -9988,8 +10004,11 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 	}
 
 	power_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
-	if (intel_display_power_get_if_enabled(dev_priv, power_domain)) {
 	WARN_ON(power_domain_mask & BIT_ULL(power_domain));
+
+	wf = intel_display_power_get_if_enabled(dev_priv, power_domain);
+	if (wf) {
+		wakerefs[power_domain] = wf;
 		power_domain_mask |= BIT_ULL(power_domain);
 
 		if (INTEL_GEN(dev_priv) >= 9)
@@ -10021,7 +10040,8 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 
 out:
 	for_each_power_domain(power_domain, power_domain_mask)
-		intel_display_power_put_unchecked(dev_priv, power_domain);
+		intel_display_power_put(dev_priv,
+					power_domain, wakerefs[power_domain]);
 
 	return active;
 }