drm/i915: Disable HPD interrupt on pin when irq storm is detected (v3)
authorEgbert Eich <eich@suse.de>
Tue, 16 Apr 2013 11:36:57 +0000 (13:36 +0200)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Thu, 18 Apr 2013 07:43:30 +0000 (09:43 +0200)
This patch disables hotplug interrupts if an 'interrupt storm'
has been detected.
Noise on the interrupt line renders the hotplug interrupt useless:
each hotplug event causes the devices to be rescanned which will
will only increase the system load.
Thus disable the hotplug interrupts and fall back to periodic
device polling.

v2: Fixed cleanup typo.
v3: Fixed format issues, clarified a variable name,
    changed pr_warn() to DRM_INFO() as suggested by
    Jani Nikula <jani.nikula@linux.intel.com>.

Signed-off-by: Egbert Eich <eich@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_irq.c

index b59df6e989cbcdcfa157bc8138d146203091023c..565ea96f772fda9f930ab019c973dfcb63be88fa 100644 (file)
@@ -88,7 +88,8 @@ static const u32 hpd_status_i915[] = { /* i915 and valleyview are the same */
        [HPD_PORT_D] = PORTD_HOTPLUG_INT_STATUS
 };
 
-
+static void ibx_hpd_irq_setup(struct drm_device *dev);
+static void i915_hpd_irq_setup(struct drm_device *dev);
 
 /* For display hotplug interrupt */
 static void
@@ -342,7 +343,11 @@ static void i915_hotplug_work_func(struct work_struct *work)
                                                    hotplug_work);
        struct drm_device *dev = dev_priv->dev;
        struct drm_mode_config *mode_config = &dev->mode_config;
-       struct intel_encoder *encoder;
+       struct intel_connector *intel_connector;
+       struct intel_encoder *intel_encoder;
+       struct drm_connector *connector;
+       unsigned long irqflags;
+       bool hpd_disabled = false;
 
        /* HPD irq before everything is fully set up. */
        if (!dev_priv->enable_hotplug_processing)
@@ -351,9 +356,33 @@ static void i915_hotplug_work_func(struct work_struct *work)
        mutex_lock(&mode_config->mutex);
        DRM_DEBUG_KMS("running encoder hotplug functions\n");
 
-       list_for_each_entry(encoder, &mode_config->encoder_list, base.head)
-               if (encoder->hot_plug)
-                       encoder->hot_plug(encoder);
+       spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+       list_for_each_entry(connector, &mode_config->connector_list, head) {
+               intel_connector = to_intel_connector(connector);
+               intel_encoder = intel_connector->encoder;
+               if (intel_encoder->hpd_pin > HPD_NONE &&
+                   dev_priv->hpd_stats[intel_encoder->hpd_pin].hpd_mark == HPD_MARK_DISABLED &&
+                   connector->polled == DRM_CONNECTOR_POLL_HPD) {
+                       DRM_INFO("HPD interrupt storm detected on connector %s: "
+                                "switching from hotplug detection to polling\n",
+                               drm_get_connector_name(connector));
+                       dev_priv->hpd_stats[intel_encoder->hpd_pin].hpd_mark = HPD_DISABLED;
+                       connector->polled = DRM_CONNECTOR_POLL_CONNECT
+                               | DRM_CONNECTOR_POLL_DISCONNECT;
+                       hpd_disabled = true;
+               }
+       }
+        /* if there were no outputs to poll, poll was disabled,
+         * therefore make sure it's enabled when disabling HPD on
+         * some connectors */
+       if (hpd_disabled)
+               drm_kms_helper_poll_enable(dev);
+
+       spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+
+       list_for_each_entry(intel_encoder, &mode_config->encoder_list, base.head)
+               if (intel_encoder->hot_plug)
+                       intel_encoder->hot_plug(intel_encoder);
 
        mutex_unlock(&mode_config->mutex);
 
@@ -585,13 +614,14 @@ static void gen6_queue_rps_work(struct drm_i915_private *dev_priv,
 #define HPD_STORM_DETECT_PERIOD 1000
 #define HPD_STORM_THRESHOLD 5
 
-static inline void hotplug_irq_storm_detect(struct drm_device *dev,
+static inline bool 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;
+       bool ret = false;
 
        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
 
@@ -609,12 +639,15 @@ static inline void hotplug_irq_storm_detect(struct drm_device *dev,
                } 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);
+                       ret = true;
                } else {
                        dev_priv->hpd_stats[i].hpd_cnt++;
                }
        }
 
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+
+       return ret;
 }
 
 static void gmbus_irq_handler(struct drm_device *dev)
@@ -690,7 +723,8 @@ static irqreturn_t valleyview_irq_handler(int irq, void *arg)
                        DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x\n",
                                         hotplug_status);
                        if (hotplug_trigger) {
-                               hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_status_i915);
+                               if (hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_status_i915))
+                                       i915_hpd_irq_setup(dev);
                                queue_work(dev_priv->wq,
                                           &dev_priv->hotplug_work);
                        }
@@ -720,7 +754,8 @@ static void ibx_irq_handler(struct drm_device *dev, u32 pch_iir)
        u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK;
 
        if (hotplug_trigger) {
-               hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_ibx);
+               if (hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_ibx))
+                       ibx_hpd_irq_setup(dev);
                queue_work(dev_priv->wq, &dev_priv->hotplug_work);
        }
        if (pch_iir & SDE_AUDIO_POWER_MASK)
@@ -768,7 +803,8 @@ static void cpt_irq_handler(struct drm_device *dev, u32 pch_iir)
        u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_CPT;
 
        if (hotplug_trigger) {
-               hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_cpt);
+               if (hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_cpt))
+                       ibx_hpd_irq_setup(dev);
                queue_work(dev_priv->wq, &dev_priv->hotplug_work);
        }
        if (pch_iir & SDE_AUDIO_POWER_MASK_CPT)
@@ -2130,11 +2166,13 @@ static void ibx_hpd_irq_setup(struct drm_device *dev)
        if (HAS_PCH_IBX(dev)) {
                mask &= ~SDE_HOTPLUG_MASK;
                list_for_each_entry(intel_encoder, &mode_config->encoder_list, base.head)
-                       mask |= hpd_ibx[intel_encoder->hpd_pin];
+                       if (dev_priv->hpd_stats[intel_encoder->hpd_pin].hpd_mark == HPD_ENABLED)
+                               mask |= hpd_ibx[intel_encoder->hpd_pin];
        } else {
                mask &= ~SDE_HOTPLUG_MASK_CPT;
                list_for_each_entry(intel_encoder, &mode_config->encoder_list, base.head)
-                       mask |= hpd_cpt[intel_encoder->hpd_pin];
+                       if (dev_priv->hpd_stats[intel_encoder->hpd_pin].hpd_mark == HPD_ENABLED)
+                               mask |= hpd_cpt[intel_encoder->hpd_pin];
        }
 
        I915_WRITE(SDEIMR, ~mask);
@@ -2669,7 +2707,8 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
                        DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x\n",
                                  hotplug_status);
                        if (hotplug_trigger) {
-                               hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_status_i915);
+                               if (hotplug_irq_storm_detect(dev, hotplug_trigger, hpd_status_i915))
+                                       i915_hpd_irq_setup(dev);
                                queue_work(dev_priv->wq,
                                           &dev_priv->hotplug_work);
                        }
@@ -2819,7 +2858,7 @@ static void i915_hpd_irq_setup(struct drm_device *dev)
 {
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        struct drm_mode_config *mode_config = &dev->mode_config;
-       struct intel_encoder *encoder;
+       struct intel_encoder *intel_encoder;
        u32 hotplug_en;
 
        if (I915_HAS_HOTPLUG(dev)) {
@@ -2827,8 +2866,9 @@ static void i915_hpd_irq_setup(struct drm_device *dev)
                hotplug_en &= ~HOTPLUG_INT_EN_MASK;
                /* Note HDMI and DP share hotplug bits */
                /* enable bits are the same for all generations */
-               list_for_each_entry(encoder, &mode_config->encoder_list, base.head)
-                       hotplug_en |= hpd_mask_i915[encoder->hpd_pin];
+               list_for_each_entry(intel_encoder, &mode_config->encoder_list, base.head)
+                       if (dev_priv->hpd_stats[intel_encoder->hpd_pin].hpd_mark == HPD_ENABLED)
+                               hotplug_en |= hpd_mask_i915[intel_encoder->hpd_pin];
                /* Programming the CRT detection parameters tends
                   to generate a spurious hotplug event about three
                   seconds later.  So just do it once.
@@ -2906,8 +2946,9 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
                        DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x\n",
                                  hotplug_status);
                        if (hotplug_trigger) {
-                               hotplug_irq_storm_detect(dev, hotplug_trigger,
-                                                        IS_G4X(dev) ? hpd_status_gen4 : hpd_status_i965);
+                               if (hotplug_irq_storm_detect(dev, hotplug_trigger,
+                                                           IS_G4X(dev) ? hpd_status_gen4 : hpd_status_i965))
+                                       i915_hpd_irq_setup(dev);
                                queue_work(dev_priv->wq,
                                           &dev_priv->hotplug_work);
                        }