drm/i915: abstract hpd irq storm detection

Simplify intel_hpd_irq_handler() by extracting HPD irq storm detection
to a separate function.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index e4260b0..eb52a03 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1375,6 +1375,45 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
 #define HPD_STORM_DETECT_PERIOD 1000
 #define HPD_STORM_THRESHOLD 5
 
+/**
+ * intel_hpd_irq_storm - gather stats and detect HPD irq storm on a pin
+ * @dev_priv: private driver data pointer
+ * @pin: the pin to gather stats on
+ *
+ * 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.
+ *
+ * @HPD_STORM_THRESHOLD irqs are allowed within @HPD_STORM_DETECT_PERIOD ms,
+ * otherwise it's considered an irq storm, and the irq state is set to
+ * @HPD_MARK_DISABLED.
+ *
+ * Return true if an irq storm was detected on @pin.
+ */
+static bool intel_hpd_irq_storm(struct drm_i915_private *dev_priv,
+                               enum hpd_pin pin)
+{
+       unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies;
+       unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD);
+       bool storm = 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 > HPD_STORM_THRESHOLD) {
+               dev_priv->hotplug.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);
+       }
+
+       return storm;
+}
+
 static bool pch_port_hotplug_long_detect(enum port port, u32 val)
 {
        switch (port) {
@@ -1544,21 +1583,9 @@ static void intel_hpd_irq_handler(struct drm_device *dev,
                        queue_hp = true;
                }
 
-               if (!time_in_range(jiffies, dev_priv->hotplug.stats[i].last_jiffies,
-                                  dev_priv->hotplug.stats[i].last_jiffies
-                                  + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD))) {
-                       dev_priv->hotplug.stats[i].last_jiffies = jiffies;
-                       dev_priv->hotplug.stats[i].count = 0;
-                       DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: 0\n", i);
-               } else if (dev_priv->hotplug.stats[i].count > HPD_STORM_THRESHOLD) {
-                       dev_priv->hotplug.stats[i].state = HPD_MARK_DISABLED;
+               if (intel_hpd_irq_storm(dev_priv, i)) {
                        dev_priv->hotplug.event_bits &= ~BIT(i);
-                       DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", i);
                        storm_detected = true;
-               } else {
-                       dev_priv->hotplug.stats[i].count++;
-                       DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", i,
-                                     dev_priv->hotplug.stats[i].count);
                }
        }