[Intel-gfx] [PATCH 2/2] drm/i915: Request no slices if no active pipes

[Mika Kuoppala]

Skip the hardware dbuf slice update if we don't have active
pipes. With no active pipes, we don't have powerwell and thus
programming the dbuf slice counts leads to accessing
hardware without runtime pm ref.

Cc: Imre Deak <imre.deak at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c    | 32 +++++++++++++++----------
 drivers/gpu/drm/i915/intel_drv.h        |  3 +--
 drivers/gpu/drm/i915/intel_runtime_pm.c | 12 ++++++++--
 3 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 05125c7c2aa1..0514b89611ac 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12644,23 +12644,23 @@ static void skl_update_crtcs(struct drm_atomic_state *state)
 	struct intel_crtc *intel_crtc;
 	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
 	struct intel_crtc_state *cstate;
-	unsigned int updated = 0;
+	unsigned int updated = 0, active_count = 0;
+	u8 required_slices;
 	bool progress;
 	enum pipe pipe;
 	int i;
-	u8 hw_enabled_slices = dev_priv->wm.skl_hw.ddb.enabled_slices;
-	u8 required_slices = intel_state->wm_results.ddb.enabled_slices;
-
 	const struct skl_ddb_entry *entries[I915_MAX_PIPES] = {};
 
-	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i)
+	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
 		/* ignore allocations for crtc's that have been turned off. */
-		if (new_crtc_state->active)
+		if (new_crtc_state->active) {
+			active_count++;
 			entries[i] = &to_intel_crtc_state(old_crtc_state)->wm.skl.ddb;
+		}
+	}
 
-	/* If 2nd DBuf slice required, enable it here */
-	if (INTEL_GEN(dev_priv) >= 11 && required_slices > hw_enabled_slices)
-		icl_dbuf_slices_update(dev_priv, required_slices);
+	required_slices = active_count ? intel_state->wm_results.ddb.enabled_slices : 0;
+	intel_dbuf_slices_update(dev_priv, required_slices);
 
 	/*
 	 * Whenever the number of active pipes changes, we need to make sure we
@@ -12670,6 +12670,7 @@ static void skl_update_crtcs(struct drm_atomic_state *state)
 	 */
 	do {
 		progress = false;
+		active_count = 0;
 
 		for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
 			bool vbl_wait = false;
@@ -12679,7 +12680,12 @@ static void skl_update_crtcs(struct drm_atomic_state *state)
 			cstate = to_intel_crtc_state(new_crtc_state);
 			pipe = intel_crtc->pipe;
 
-			if (updated & cmask || !cstate->base.active)
+			if (!cstate->base.active)
+				continue;
+
+			active_count++;
+
+			if (updated & cmask)
 				continue;
 
 			if (skl_ddb_allocation_overlaps(dev_priv,
@@ -12713,9 +12719,9 @@ static void skl_update_crtcs(struct drm_atomic_state *state)
 		}
 	} while (progress);
 
-	/* If 2nd DBuf slice is no more required disable it */
-	if (INTEL_GEN(dev_priv) >= 11 && required_slices < hw_enabled_slices)
-		icl_dbuf_slices_update(dev_priv, required_slices);
+
+	required_slices = active_count ? intel_state->wm_results.ddb.enabled_slices : 0;
+	intel_dbuf_slices_update(dev_priv, required_slices);
 }
 
 static void intel_atomic_helper_free_state(struct drm_i915_private *dev_priv)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 21819a9bdcae..d643f8877097 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -2086,8 +2086,7 @@ bool intel_display_power_get_if_enabled(struct drm_i915_private *dev_priv,
 					enum intel_display_power_domain domain);
 void intel_display_power_put(struct drm_i915_private *dev_priv,
 			     enum intel_display_power_domain domain);
-void icl_dbuf_slices_update(struct drm_i915_private *dev_priv,
-			    u8 req_slices);
+void intel_dbuf_slices_update(struct drm_i915_private *dev_priv, u8 req_slices);
 
 static inline void
 assert_rpm_device_not_suspended(struct drm_i915_private *dev_priv)
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 770de2632530..3a271ac22fec 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -3233,8 +3233,8 @@ static u8 intel_dbuf_max_slices(struct drm_i915_private *dev_priv)
 	return 2;
 }
 
-void icl_dbuf_slices_update(struct drm_i915_private *dev_priv,
-			    u8 req_slices)
+static void icl_dbuf_slices_update(struct drm_i915_private *dev_priv,
+				   const u8 req_slices)
 {
 	const u8 hw_enabled_slices = dev_priv->wm.skl_hw.ddb.enabled_slices;
 	bool ret;
@@ -3256,6 +3256,14 @@ void icl_dbuf_slices_update(struct drm_i915_private *dev_priv,
 		dev_priv->wm.skl_hw.ddb.enabled_slices = req_slices;
 }
 
+void intel_dbuf_slices_update(struct drm_i915_private *dev_priv, u8 slices)
+{
+	if (INTEL_GEN(dev_priv) < 11)
+		return;
+
+	icl_dbuf_slices_update(dev_priv, slices);
+}
+
 static void icl_dbuf_enable(struct drm_i915_private *dev_priv)
 {
 	I915_WRITE(DBUF_CTL_S1, I915_READ(DBUF_CTL_S1) | DBUF_POWER_REQUEST);
-- 
2.17.1