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 at linux.intel.com>. Signed-off-by: Egbert Eich <eich at suse.de> --- drivers/gpu/drm/i915/i915_irq.c | 75 +++++++++++++++++++++++++++++++---------- 1 file changed, 58 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index a3f1ac4..834c717 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -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); @@ -584,13 +613,14 @@ static void gen6_queue_rps_work(struct drm_i915_private *dev_priv, #define HPD_STORM_DETECT_PERIOD 1000 -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); @@ -605,12 +635,15 @@ static inline void hotplug_irq_storm_detect(struct drm_device *dev, } else if (dev_priv->hpd_stats[i].hpd_cnt > 5) { 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) @@ -686,7 +719,8 @@ 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); } @@ -716,7 +750,8 @@ 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) @@ -764,7 +799,8 @@ 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) @@ -2119,11 +2155,13 @@ 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); @@ -2651,7 +2689,8 @@ 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); } @@ -2801,7 +2840,7 @@ 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)) { @@ -2809,8 +2848,9 @@ 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. @@ -2888,8 +2928,9 @@ 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); } -- 1.8.1.4