[PATCH v3 Update] drm/i915: Add bit field to record which pins have received HPD events (v3)

[Egbert Eich <eich@suse.de>]

This allows to add code which limits 're'-detect() of displays to connectors
that have received an HPD event.

v2: Reordered drm_i915_private: Move hpd_event_bits to hpd state tracking.
v3: Fixed merge conflicts with previous patches, removed some noisy debug
    logging as suggested by Jani Nikula.

Signed-off-by: Egbert Eich <eich@suse.de>
---
(Sorry for the spam, I had accidenty went the wrong version of this patch)

 drivers/gpu/drm/i915/i915_drv.h |  1 +
 drivers/gpu/drm/i915/i915_irq.c | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 195b9fe..c0d9fb9 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -938,6 +938,7 @@ typedef struct drm_i915_private {
 			HPD_MARK_DISABLED = 2
 		} hpd_mark;
 	} hpd_stats[HPD_NUM_PINS];
+	u32 hpd_event_bits;
 	struct timer_list hotplug_reenable_timer;
 
 	int num_pch_pll;
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index f60c643..6e643d7 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -350,6 +350,7 @@ static void i915_hotplug_work_func(struct work_struct *work)
 	struct drm_connector *connector;
 	unsigned long irqflags;
 	bool hpd_disabled = false;
+	u32 hpd_event_bits;
 
 	/* HPD irq before everything is fully set up. */
 	if (!dev_priv->enable_hotplug_processing)
@@ -359,6 +360,9 @@ static void i915_hotplug_work_func(struct work_struct *work)
 	DRM_DEBUG_KMS("running encoder hotplug functions\n");
 
 	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+
+	hpd_event_bits = dev_priv->hpd_event_bits;
+	dev_priv->hpd_event_bits = 0;
 	list_for_each_entry(connector, &mode_config->connector_list, head) {
 		intel_connector = to_intel_connector(connector);
 		intel_encoder = intel_connector->encoder;
@@ -373,6 +377,12 @@ static void i915_hotplug_work_func(struct work_struct *work)
 				| DRM_CONNECTOR_POLL_DISCONNECT;
 			hpd_disabled = true;
 		}
+#if 0
+		if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) {
+			DRM_DEBUG_KMS("Connector %s (pin %i) received hotplug event.\n",
+				      drm_get_connector_name(connector), intel_encoder->hpd_pin);
+		}
+#endif
 	}
 	 /* if there were no outputs to poll, poll was disabled,
 	  * therefore make sure it's enabled when disabling HPD on
@@ -632,6 +642,7 @@ static inline bool hotplug_irq_storm_detect(struct drm_device *dev,
 	for (i = 1; i < HPD_NUM_PINS; i++) {
 		if ((hpd[i] & hotplug_trigger) &&
 		    dev_priv->hpd_stats[i].hpd_mark == HPD_ENABLED) {
+			dev_priv->hpd_event_bits |= (1 << i);
 			if (!time_in_range(jiffies, dev_priv->hpd_stats[i].hpd_last_jiffies,
 					  dev_priv->hpd_stats[i].hpd_last_jiffies
 					  + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD))) {
@@ -639,6 +650,7 @@ static inline bool hotplug_irq_storm_detect(struct drm_device *dev,
 				dev_priv->hpd_stats[i].hpd_cnt = 0;
 			} else if (dev_priv->hpd_stats[i].hpd_cnt > 5) {
 				dev_priv->hpd_stats[i].hpd_mark = HPD_MARK_DISABLED;
+				dev_priv->hpd_event_bits &= ~(1 << i);
 				DRM_DEBUG_KMS("HPD interrupt storm detected on  PIN %d\n", i);
 				ret = true;
 			} else
-- 
1.8.1.4