Merge tag 'v5.1' into next

Sync up with mainline to bring in the latest APIs.

1 files changed, 47 insertions, 28 deletions

diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
index 9a8018130237..b8937c788f03 100644
--- a/drivers/gpu/drm/i915/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/intel_hotplug.c
@@ -23,7 +23,6 @@
 
 #include <linux/kernel.h>
 
-#include <drm/drmP.h>
 #include <drm/i915_drm.h>
 
 #include "i915_drv.h"
@@ -114,51 +113,68 @@ enum hpd_pin intel_hpd_pin_default(struct drm_i915_private *dev_priv,
 #define HPD_STORM_REENABLE_DELAY	(2 * 60 * 1000)
 
 /**
- * intel_hpd_irq_storm_detect - gather stats and detect HPD irq storm on a pin
+ * intel_hpd_irq_storm_detect - gather stats and detect HPD IRQ storm on a pin
  * @dev_priv: private driver data pointer
  * @pin: the pin to gather stats on
+ * @long_hpd: whether the HPD IRQ was long or short
  *
- * Gather stats about HPD irqs from the specified @pin, and detect irq
+ * Gather stats about HPD IRQs from the specified @pin, and detect IRQ
  * storms. Only the pin specific stats and state are changed, the caller is
  * responsible for further action.
  *
- * The number of irqs that are allowed within @HPD_STORM_DETECT_PERIOD is
+ * The number of IRQs that are allowed within @HPD_STORM_DETECT_PERIOD is
  * stored in @dev_priv->hotplug.hpd_storm_threshold which defaults to
- * @HPD_STORM_DEFAULT_THRESHOLD. If this threshold is exceeded, it's
- * considered an irq storm and the irq state is set to @HPD_MARK_DISABLED.
+ * @HPD_STORM_DEFAULT_THRESHOLD. Long IRQs count as +10 to this threshold, and
+ * short IRQs count as +1. If this threshold is exceeded, it's considered an
+ * IRQ storm and the IRQ state is set to @HPD_MARK_DISABLED.
+ *
+ * By default, most systems will only count long IRQs towards
+ * &dev_priv->hotplug.hpd_storm_threshold. However, some older systems also
+ * suffer from short IRQ storms and must also track these. Because short IRQ
+ * storms are naturally caused by sideband interactions with DP MST devices,
+ * short IRQ detection is only enabled for systems without DP MST support.
+ * Systems which are new enough to support DP MST are far less likely to
+ * suffer from IRQ storms at all, so this is fine.
  *
  * The HPD threshold can be controlled through i915_hpd_storm_ctl in debugfs,
  * and should only be adjusted for automated hotplug testing.
  *
- * Return true if an irq storm was detected on @pin.
+ * Return true if an IRQ storm was detected on @pin.
  */
 static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv,
-				       enum hpd_pin pin)
+				       enum hpd_pin pin, bool long_hpd)
 {
-	unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies;
+	struct i915_hotplug *hpd = &dev_priv->hotplug;
+	unsigned long start = hpd->stats[pin].last_jiffies;
 	unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD);
-	const int threshold = dev_priv->hotplug.hpd_storm_threshold;
+	const int increment = long_hpd ? 10 : 1;
+	const int threshold = hpd->hpd_storm_threshold;
 	bool storm = false;
 
+	if (!threshold ||
+	    (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled))
+		return false;
+
 	if (!time_in_range(jiffies, start, end)) {
-		dev_priv->hotplug.stats[pin].last_jiffies = jiffies;
-		dev_priv->hotplug.stats[pin].count = 0;
-		DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: 0\n", pin);
-	} else if (dev_priv->hotplug.stats[pin].count > threshold &&
-		   threshold) {
-		dev_priv->hotplug.stats[pin].state = HPD_MARK_DISABLED;
+		hpd->stats[pin].last_jiffies = jiffies;
+		hpd->stats[pin].count = 0;
+	}
+
+	hpd->stats[pin].count += increment;
+	if (hpd->stats[pin].count > threshold) {
+		hpd->stats[pin].state = HPD_MARK_DISABLED;
 		DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", pin);
 		storm = true;
 	} else {
-		dev_priv->hotplug.stats[pin].count++;
 		DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", pin,
-			      dev_priv->hotplug.stats[pin].count);
+			      hpd->stats[pin].count);
 	}
 
 	return storm;
 }
 
-static void intel_hpd_irq_storm_disable(struct drm_i915_private *dev_priv)
+static void
+intel_hpd_irq_storm_switch_to_polling(struct drm_i915_private *dev_priv)
 {
 	struct drm_device *dev = &dev_priv->drm;
 	struct intel_connector *intel_connector;
@@ -210,9 +226,10 @@ static void intel_hpd_irq_storm_reenable_work(struct work_struct *work)
 		container_of(work, typeof(*dev_priv),
 			     hotplug.reenable_work.work);
 	struct drm_device *dev = &dev_priv->drm;
+	intel_wakeref_t wakeref;
 	enum hpd_pin pin;
 
-	intel_runtime_pm_get(dev_priv);
+	wakeref = intel_runtime_pm_get(dev_priv);
 
 	spin_lock_irq(&dev_priv->irq_lock);
 	for_each_hpd_pin(pin) {
@@ -245,7 +262,7 @@ static void intel_hpd_irq_storm_reenable_work(struct work_struct *work)
 		dev_priv->display.hpd_irq_setup(dev_priv);
 	spin_unlock_irq(&dev_priv->irq_lock);
 
-	intel_runtime_pm_put(dev_priv);
+	intel_runtime_pm_put(dev_priv, wakeref);
 }
 
 bool intel_encoder_hotplug(struct intel_encoder *encoder,
@@ -348,8 +365,8 @@ static void i915_hotplug_work_func(struct work_struct *work)
 	hpd_event_bits = dev_priv->hotplug.event_bits;
 	dev_priv->hotplug.event_bits = 0;
 
-	/* Disable hotplug on connectors that hit an irq storm. */
-	intel_hpd_irq_storm_disable(dev_priv);
+	/* Enable polling for connectors which had HPD IRQ storms */
+	intel_hpd_irq_storm_switch_to_polling(dev_priv);
 
 	spin_unlock_irq(&dev_priv->irq_lock);
 
@@ -453,7 +470,7 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv,
 			 * hotplug bits itself. So only WARN about unexpected
 			 * interrupts on saner platforms.
 			 */
-			WARN_ONCE(!HAS_GMCH_DISPLAY(dev_priv),
+			WARN_ONCE(!HAS_GMCH(dev_priv),
 				  "Received HPD interrupt on pin %d although disabled\n", pin);
 			continue;
 		}
@@ -474,15 +491,17 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv,
 			queue_hp = true;
 		}
 
-		if (!long_hpd)
-			continue;
-
-		if (intel_hpd_irq_storm_detect(dev_priv, pin)) {
+		if (intel_hpd_irq_storm_detect(dev_priv, pin, long_hpd)) {
 			dev_priv->hotplug.event_bits &= ~BIT(pin);
 			storm_detected = true;
+			queue_hp = true;
 		}
 	}
 
+	/*
+	 * Disable any IRQs that storms were detected on. Polling enablement
+	 * happens later in our hotplug work.
+	 */
 	if (storm_detected && dev_priv->display_irqs_enabled)
 		dev_priv->display.hpd_irq_setup(dev_priv);
 	spin_unlock(&dev_priv->irq_lock);