[PATCH v3 5/5] drm/i915/crt: Use intel_hpd_block/unblock() instead of intel_hpd_disable/enable()

[Imre Deak <imre.deak@intel.com>]

intel_hpd_disable/enable() have the same purpose as
intel_hpd_block/unblock(), except that disable/enable will drop any HPD
IRQs which were triggered while the HPD was disabled, while
block/unblock will handle such IRQs after the IRQ handling is unblocked.
Use intel_hpd_block/unblock() for crt as well, by adding a helper to
explicitly clear any pending IRQs before unblocking.

v2:
- Handle encoders without a port assigned to them.
- Rebase on change in intel_hpd_suspend() documentation.
v3:
- Rebase on the suspend/resume -> block/unblock rename change.
- Clear the pending events only after all encoders have unblocked the
  HPD handling.
- Clear the short/long port events for all encoders using the given HPD
  pin.

Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_crt.c     |  7 +--
 drivers/gpu/drm/i915/display/intel_hotplug.c | 62 +++++++++++---------
 drivers/gpu/drm/i915/display/intel_hotplug.h |  3 +-
 3 files changed, 37 insertions(+), 35 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_crt.c b/drivers/gpu/drm/i915/display/intel_crt.c
index 321580b095e7d..e8a2f28e662ec 100644
--- a/drivers/gpu/drm/i915/display/intel_crt.c
+++ b/drivers/gpu/drm/i915/display/intel_crt.c
@@ -531,8 +531,6 @@ static bool valleyview_crt_detect_hotplug(struct drm_connector *connector)
 {
 	struct intel_display *display = to_intel_display(connector->dev);
 	struct intel_crt *crt = intel_attached_crt(to_intel_connector(connector));
-	struct drm_i915_private *dev_priv = to_i915(connector->dev);
-	bool reenable_hpd;
 	u32 adpa;
 	bool ret;
 	u32 save_adpa;
@@ -549,7 +547,7 @@ static bool valleyview_crt_detect_hotplug(struct drm_connector *connector)
 	 *
 	 * Just disable HPD interrupts here to prevent this
 	 */
-	reenable_hpd = intel_hpd_disable(dev_priv, crt->base.hpd_pin);
+	intel_hpd_block(&crt->base);
 
 	save_adpa = adpa = intel_de_read(display, crt->adpa_reg);
 	drm_dbg_kms(display->drm,
@@ -576,8 +574,7 @@ static bool valleyview_crt_detect_hotplug(struct drm_connector *connector)
 	drm_dbg_kms(display->drm,
 		    "valleyview hotplug adpa=0x%x, result %d\n", adpa, ret);
 
-	if (reenable_hpd)
-		intel_hpd_enable(dev_priv, crt->base.hpd_pin);
+	intel_hpd_clear_and_unblock(&crt->base);
 
 	return ret;
 }
diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c b/drivers/gpu/drm/i915/display/intel_hotplug.c
index 6c6b7d661d639..b0079c6efa83d 100644
--- a/drivers/gpu/drm/i915/display/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/display/intel_hotplug.c
@@ -1017,33 +1017,6 @@ void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
 		drm_dbg_kms(&dev_priv->drm, "Hotplug detection work still active\n");
 }
 
-bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
-{
-	bool ret = false;
-
-	if (pin == HPD_NONE)
-		return false;
-
-	spin_lock_irq(&dev_priv->irq_lock);
-	if (dev_priv->display.hotplug.stats[pin].state == HPD_ENABLED) {
-		dev_priv->display.hotplug.stats[pin].state = HPD_DISABLED;
-		ret = true;
-	}
-	spin_unlock_irq(&dev_priv->irq_lock);
-
-	return ret;
-}
-
-void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
-{
-	if (pin == HPD_NONE)
-		return;
-
-	spin_lock_irq(&dev_priv->irq_lock);
-	dev_priv->display.hotplug.stats[pin].state = HPD_ENABLED;
-	spin_unlock_irq(&dev_priv->irq_lock);
-}
-
 static void queue_work_for_missed_irqs(struct drm_i915_private *i915)
 {
 	struct intel_display *display = to_intel_display(&i915->drm);
@@ -1121,7 +1094,8 @@ static bool unblock_hpd_pin(struct intel_display *display, enum hpd_pin pin)
  *   drm_connector_funcs::detect()) remains allowed, for instance as part of
  *   userspace connector probing, or DRM core's connector polling.
  *
- * The call must be followed by calling intel_hpd_unblock().
+ * The call must be followed by calling intel_hpd_unblock(), or
+ * intel_hpd_clear_and_unblock().
  *
  * Note that the handling of HPD IRQs for another encoder using the same HPD
  * pin as that of @encoder will be also blocked.
@@ -1172,6 +1146,38 @@ void intel_hpd_unblock(struct intel_encoder *encoder)
 	spin_unlock_irq(&i915->irq_lock);
 }
 
+/**
+ * intel_hpd_clear_and_unblock - Unblock handling of new HPD IRQs on an HPD pin
+ * @encoder: Encoder to unblock the HPD handling for
+ *
+ * Unblock the handling of HPD IRQs on the HPD pin of @encoder, which was
+ * previously blocked by intel_hpd_block(). Any HPD IRQ raised on the
+ * HPD pin while it was blocked will be cleared, handling only new IRQs.
+ */
+void intel_hpd_clear_and_unblock(struct intel_encoder *encoder)
+{
+	struct intel_display *display = to_intel_display(encoder);
+	struct drm_i915_private *i915 = to_i915(display->drm);
+	struct intel_hotplug *hotplug = &display->hotplug;
+	u32 blocked_ports;
+
+	if (encoder->hpd_pin == HPD_NONE)
+		return;
+
+	blocked_ports = hpd_pin_mask_to_ports(display, BIT(encoder->hpd_pin));
+
+	spin_lock_irq(&i915->irq_lock);
+
+	if (unblock_hpd_pin(display, encoder->hpd_pin)) {
+		hotplug->event_bits &= ~BIT(encoder->hpd_pin);
+		hotplug->retry_bits &= ~BIT(encoder->hpd_pin);
+		hotplug->short_port_mask &= ~blocked_ports;
+		hotplug->long_port_mask &= ~blocked_ports;
+	}
+
+	spin_unlock_irq(&i915->irq_lock);
+}
+
 void intel_hpd_enable_detection_work(struct drm_i915_private *i915)
 {
 	spin_lock_irq(&i915->irq_lock);
diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.h b/drivers/gpu/drm/i915/display/intel_hotplug.h
index 5f9857136f5e3..f189b871904ed 100644
--- a/drivers/gpu/drm/i915/display/intel_hotplug.h
+++ b/drivers/gpu/drm/i915/display/intel_hotplug.h
@@ -26,10 +26,9 @@ void intel_hpd_init(struct drm_i915_private *dev_priv);
 void intel_hpd_init_early(struct drm_i915_private *i915);
 void intel_hpd_cancel_work(struct drm_i915_private *dev_priv);
 enum hpd_pin intel_hpd_pin_default(enum port port);
-bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin);
-void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin);
 void intel_hpd_block(struct intel_encoder *encoder);
 void intel_hpd_unblock(struct intel_encoder *encoder);
+void intel_hpd_clear_and_unblock(struct intel_encoder *encoder);
 void intel_hpd_debugfs_register(struct drm_i915_private *i915);
 
 void intel_hpd_enable_detection_work(struct drm_i915_private *i915);
-- 
2.44.2