drm/i915: Add HPD IRQ storm detection (v5)

[linux-imx.git] / drivers / gpu / drm / i915 / i915_irq.c

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index e97bbb2abd59dab1061e928bf3c5ba51f5ec82c7..5ac1291c5853f737edcf6b28aedc469e8d8f7cfe 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -582,6 +582,40 @@ static void gen6_queue_rps_work(struct drm_i915_private *dev_priv,
        queue_work(dev_priv->wq, &dev_priv->rps.work);
 }
 
+#define HPD_STORM_DETECT_PERIOD 1000
+#define HPD_STORM_THRESHOLD 5
+
+static inline void hotplug_irq_storm_detect(struct drm_device *dev,
+                                           u32 hotplug_trigger,
+                                           const u32 *hpd)
+{
+       drm_i915_private_t *dev_priv = dev->dev_private;
+       unsigned long irqflags;
+       int i;
+
+       spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+
+       for (i = 1; i < HPD_NUM_PINS; i++) {
+               if (!(hpd[i] & hotplug_trigger) ||
+                   dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED)
+                       continue;
+
+               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))) {
+                       dev_priv->hpd_stats[i].hpd_last_jiffies = jiffies;
+                       dev_priv->hpd_stats[i].hpd_cnt = 0;
+               } else if (dev_priv->hpd_stats[i].hpd_cnt > HPD_STORM_THRESHOLD) {
+                       dev_priv->hpd_stats[i].hpd_mark = HPD_MARK_DISABLED;
+                       DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", i);
+               } else {
+                       dev_priv->hpd_stats[i].hpd_cnt++;
+               }
+       }
+
+       spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+}
+
 static void gmbus_irq_handler(struct drm_device *dev)
 {
        struct drm_i915_private *dev_priv = (drm_i915_private_t *) dev->dev_private;
@@ -650,13 +684,15 @@ static irqreturn_t valleyview_irq_handler(int irq, void *arg)
                /* Consume port.  Then clear IIR or we'll miss events */
                if (iir & I915_DISPLAY_PORT_INTERRUPT) {
                        u32 hotplug_status = I915_READ(PORT_HOTPLUG_STAT);
+                       u32 hotplug_trigger = hotplug_status & HOTPLUG_INT_STATUS_I915;
 
                        DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x\n",
                                         hotplug_status);
-                       if (hotplug_status & HOTPLUG_INT_STATUS_I915)
+                       if (hotplug_trigger) {
+                               hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_status_i915);
                                queue_work(dev_priv->wq,
                                           &dev_priv->hotplug_work);
-
+                       }
                        I915_WRITE(PORT_HOTPLUG_STAT, hotplug_status);
                        I915_READ(PORT_HOTPLUG_STAT);
                }
@@ -680,10 +716,12 @@ static void ibx_irq_handler(struct drm_device *dev, u32 pch_iir)
 {
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        int pipe;
+       u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK;
 
-       if (pch_iir & SDE_HOTPLUG_MASK)
+       if (hotplug_trigger) {
+               hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_ibx);
                queue_work(dev_priv->wq, &dev_priv->hotplug_work);
-
+       }
        if (pch_iir & SDE_AUDIO_POWER_MASK)
                DRM_DEBUG_DRIVER("PCH audio power change on port %d\n",
                                 (pch_iir & SDE_AUDIO_POWER_MASK) >>
@@ -726,10 +764,12 @@ static void cpt_irq_handler(struct drm_device *dev, u32 pch_iir)
 {
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        int pipe;
+       u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_CPT;
 
-       if (pch_iir & SDE_HOTPLUG_MASK_CPT)
+       if (hotplug_trigger) {
+               hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_cpt);
                queue_work(dev_priv->wq, &dev_priv->hotplug_work);
-
+       }
        if (pch_iir & SDE_AUDIO_POWER_MASK_CPT)
                DRM_DEBUG_DRIVER("PCH audio power change on port %d\n",
                                 (pch_iir & SDE_AUDIO_POWER_MASK_CPT) >>
@@ -2621,13 +2661,15 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
                if ((I915_HAS_HOTPLUG(dev)) &&
                    (iir & I915_DISPLAY_PORT_INTERRUPT)) {
                        u32 hotplug_status = I915_READ(PORT_HOTPLUG_STAT);
+                       u32 hotplug_trigger = hotplug_status & HOTPLUG_INT_STATUS_I915;
 
                        DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x\n",
                                  hotplug_status);
-                       if (hotplug_status & HOTPLUG_INT_STATUS_I915)
+                       if (hotplug_trigger) {
+                               hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_status_i915);
                                queue_work(dev_priv->wq,
                                           &dev_priv->hotplug_work);
-
+                       }
                        I915_WRITE(PORT_HOTPLUG_STAT, hotplug_status);
                        POSTING_READ(PORT_HOTPLUG_STAT);
                }
@@ -2854,15 +2896,18 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
                /* Consume port.  Then clear IIR or we'll miss events */
                if (iir & I915_DISPLAY_PORT_INTERRUPT) {
                        u32 hotplug_status = I915_READ(PORT_HOTPLUG_STAT);
+                       u32 hotplug_trigger = hotplug_status & (IS_G4X(dev) ?
+                                                                 HOTPLUG_INT_STATUS_G4X :
+                                                                 HOTPLUG_INT_STATUS_I965);
 
                        DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x\n",
                                  hotplug_status);
-                       if (hotplug_status & (IS_G4X(dev) ?
-                                             HOTPLUG_INT_STATUS_G4X :
-                                             HOTPLUG_INT_STATUS_I965))
+                       if (hotplug_trigger) {
+                               hotplug_irq_storm_detect(dev, hotplug_trigger,
+                                                        IS_G4X(dev) ? hpd_status_gen4 : hpd_status_i965);
                                queue_work(dev_priv->wq,
                                           &dev_priv->hotplug_work);
-
+                       }
                        I915_WRITE(PORT_HOTPLUG_STAT, hotplug_status);
                        I915_READ(PORT_HOTPLUG_STAT);
                }