[Intel-gfx] [PATCH] drm/i915: Track the temporary wakerefs used for hsw_get_pipe_config

[Chris Wilson]

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 at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_display.c | 42 ++++++++++++++++++++--------
 1 file changed, 30 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 7ecfb7d98839..0cca7bb8fa3f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/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 *wakeref)
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -9827,10 +9828,13 @@ 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));
+
+	wakeref[power_domain] =
+		intel_display_power_get_if_enabled(dev_priv, power_domain);
+	if (!wakeref[power_domain])
 		return false;
 
-	WARN_ON(*power_domain_mask & BIT_ULL(power_domain));
 	*power_domain_mask |= BIT_ULL(power_domain);
 
 	tmp = I915_READ(PIPECONF(pipe_config->cpu_transcoder));
@@ -9840,7 +9844,8 @@ 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 *wakeref)
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -9856,10 +9861,14 @@ 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));
+
+		wakeref[power_domain] =
+			intel_display_power_get_if_enabled(dev_priv,
+							   power_domain);
+		if (!wakeref[power_domain])
 			continue;
 
-		WARN_ON(*power_domain_mask & BIT_ULL(power_domain));
 		*power_domain_mask |= BIT_ULL(power_domain);
 
 		/*
@@ -9939,22 +9948,27 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	enum intel_display_power_domain power_domain;
+	intel_wakeref_t wakeref[POWER_DOMAIN_NUM];
 	u64 power_domain_mask;
 	bool active;
 
 	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))
+	wakeref[power_domain] =
+		intel_display_power_get_if_enabled(dev_priv, power_domain);
+	if (!wakeref[power_domain])
 		return false;
 	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, wakeref);
 
 	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, wakeref)) {
 		WARN_ON(active);
 		active = true;
 	}
@@ -9988,8 +10002,11 @@ 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));
+	WARN_ON(power_domain_mask & BIT_ULL(power_domain));
+
+	wakeref[power_domain] =
+		intel_display_power_get_if_enabled(dev_priv, power_domain);
+	if (wakeref[power_domain]) {
 		power_domain_mask |= BIT_ULL(power_domain);
 
 		if (INTEL_GEN(dev_priv) >= 9)
@@ -10021,7 +10038,8 @@ 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, wakeref[power_domain]);
 
 	return active;
 }
-- 
2.20.1