[Intel-gfx] [PATCH] drm/i915: Disable idle messaging before ring disable

[Mika Kuoppala]

According to bspec, with ring mode scheduling on gen >= 8,
we need to disable ring idle message before writing zero to
Ring Buffer Enable.

Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h         |  2 ++
 drivers/gpu/drm/i915/i915_reg.h         |  2 ++
 drivers/gpu/drm/i915/intel_ringbuffer.c | 28 +++++++++++++++++++++++++++-
 drivers/gpu/drm/i915/intel_uncore.c     | 12 ++++++++++++
 4 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1038f5c..564c593 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2609,6 +2609,8 @@ void intel_uncore_forcewake_get__locked(struct drm_i915_private *dev_priv,
 void intel_uncore_forcewake_put__locked(struct drm_i915_private *dev_priv,
 					enum forcewake_domains domains);
 void assert_forcewakes_inactive(struct drm_i915_private *dev_priv);
+void assert_forcewakes_active(struct drm_i915_private *dev_priv);
+
 static inline bool intel_vgpu_active(struct drm_device *dev)
 {
 	return to_i915(dev)->vgpu.active;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 6eeba63..9bead93 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1643,6 +1643,8 @@ enum skl_disp_power_wells {
 #define   GFX_PSMI_GRANULARITY		(1<<10)
 #define   GFX_PPGTT_ENABLE		(1<<9)
 
+#define CSPWRFSM	0x022AC
+
 #define VLV_DISPLAY_BASE 0x180000
 #define VLV_MIPI_BASE VLV_DISPLAY_BASE
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index d934f85..c06dc76 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -531,6 +531,31 @@ static void intel_ring_setup_status_page(struct intel_engine_cs *ring)
 	}
 }
 
+static void disable_ring(struct intel_engine_cs *ring)
+{
+	struct drm_i915_private *dev_priv = to_i915(ring->dev);
+	const bool need_idle_disable = ring->id == RCS &&
+		INTEL_INFO(ring->dev)->gen > 7;
+
+	assert_forcewakes_active(dev_priv);
+
+	if (need_idle_disable) {
+		I915_WRITE(RING_PSMI_CTL(ring->mmio_base),
+			   _MASKED_BIT_ENABLE(GEN6_PSMI_SLEEP_MSG_DISABLE));
+
+		if (wait_for((I915_READ(CSPWRFSM) & ((1 << 6) - 1)) == 0x30,
+			     1000))
+			DRM_ERROR("%s: disable idle msg timeout\n",
+				  ring->name);
+	}
+
+	I915_WRITE_CTL(ring, 0);
+
+	if (need_idle_disable)
+		I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
+			   _MASKED_BIT_DISABLE(GEN6_PSMI_SLEEP_MSG_DISABLE));
+}
+
 static bool stop_ring(struct intel_engine_cs *ring)
 {
 	struct drm_i915_private *dev_priv = to_i915(ring->dev);
@@ -548,7 +573,8 @@ static bool stop_ring(struct intel_engine_cs *ring)
 		}
 	}
 
-	I915_WRITE_CTL(ring, 0);
+	disable_ring(ring);
+
 	I915_WRITE_HEAD(ring, 0);
 	ring->write_tail(ring, 0);
 
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index a6d8a3e..4e070e0 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -525,6 +525,18 @@ void assert_forcewakes_inactive(struct drm_i915_private *dev_priv)
 		WARN_ON(domain->wake_count);
 }
 
+void assert_forcewakes_active(struct drm_i915_private *dev_priv)
+{
+	struct intel_uncore_forcewake_domain *domain;
+	enum forcewake_domain_id id;
+
+	if (!dev_priv->uncore.funcs.force_wake_get)
+		return;
+
+	for_each_fw_domain(domain, dev_priv, id)
+		WARN_ON(domain->wake_count == 0);
+}
+
 /* We give fast paths for the really cool registers */
 #define NEEDS_FORCE_WAKE(dev_priv, reg) \
 	 ((reg) < 0x40000 && (reg) != FORCEWAKE)
-- 
1.9.1