diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_hotplug.c')
-rw-r--r-- | drivers/gpu/drm/i915/intel_hotplug.c | 67 |
1 files changed, 43 insertions, 24 deletions
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c index 9a8018130237..e24174d08fed 100644 --- a/drivers/gpu/drm/i915/intel_hotplug.c +++ b/drivers/gpu/drm/i915/intel_hotplug.c @@ -114,51 +114,68 @@ 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; @@ -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); @@ -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); |