[Intel-gfx] [PATCH 06/11] drm/i915/psr: Add intel_psr_activate_block_get()/put()

[José Roberto de Souza]

intel_psr_activate_block_get() should be called when by some reason
PSR should not be activated for some time, it will increment counter
and it should the decremented by intel_psr_activate_block_put()
when PSR can be activated again.
intel_psr_activate_block_put() will not actually activate PSR, users
of this function should also call intel_psr_activate().

Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h  |  1 +
 drivers/gpu/drm/i915/intel_drv.h |  2 ++
 drivers/gpu/drm/i915/intel_psr.c | 54 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 99af9169d792..41ebb144594e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -609,6 +609,7 @@ struct i915_psr {
 	bool has_hw_tracking;
 	bool psr2_enabled;
 	u8 sink_sync_latency;
+	unsigned int activate_block_count;
 
 	void (*enable_source)(struct intel_dp *,
 			      const struct intel_crtc_state *);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 70026b772721..020b96324135 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1893,6 +1893,8 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
 			      struct intel_crtc_state *crtc_state);
 void intel_psr_exit(struct intel_dp *intel_dp, bool wait_idle);
 void intel_psr_activate(struct intel_dp *intel_dp, bool schedule);
+void intel_psr_activate_block_get(struct intel_dp *intel_dp);
+void intel_psr_activate_block_put(struct intel_dp *intel_dp);
 
 /* intel_runtime_pm.c */
 int intel_power_domains_init(struct drm_i915_private *);
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 906a12ea934d..8702dbafb42d 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -558,6 +558,8 @@ static void __intel_psr_activate(struct intel_dp *intel_dp)
 
 	WARN_ON(dev_priv->psr.active);
 	lockdep_assert_held(&dev_priv->psr.lock);
+	if (dev_priv->psr.activate_block_count)
+		return;
 
 	dev_priv->psr.activate(intel_dp);
 	dev_priv->psr.active = true;
@@ -1188,3 +1190,55 @@ void intel_psr_activate(struct intel_dp *intel_dp, bool schedule)
 out:
 	mutex_unlock(&dev_priv->psr.lock);
 }
+
+/**
+ * intel_psr_activate_block_get - Block further attempts to activate PSR
+ * @intel_dp: DisplayPort that have PSR enabled
+ *
+ * It have a internal reference count, so each intel_psr_activate_block_get()
+ * should have a intel_psr_activate_block_put() counterpart.
+ */
+void intel_psr_activate_block_get(struct intel_dp *intel_dp)
+{
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+
+	if (!CAN_PSR(dev_priv))
+		return;
+
+	mutex_lock(&dev_priv->psr.lock);
+	if (dev_priv->psr.enabled != intel_dp)
+		goto out;
+
+	dev_priv->psr.activate_block_count++;
+out:
+	mutex_unlock(&dev_priv->psr.lock);
+}
+
+
+/**
+ * intel_psr_activate_block_put - Unblock further attempts to activate PSR
+ * @intel_dp: DisplayPort that have PSR enabled
+ *
+ * Decrease the reference counter incremented by intel_psr_activate_block_get()
+ * when zero it allows PSR be activate. To actually activate PSR when reference
+ * counter is zero intel_psr_activate() should be called.
+ */
+void intel_psr_activate_block_put(struct intel_dp *intel_dp)
+{
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+
+	if (!CAN_PSR(dev_priv))
+		return;
+
+	mutex_lock(&dev_priv->psr.lock);
+	if (dev_priv->psr.enabled != intel_dp)
+		goto out;
+
+	dev_priv->psr.activate_block_count--;
+out:
+	mutex_unlock(&dev_priv->psr.lock);
+}
-- 
2.16.3