diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_hotplug.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_hotplug.c | 50 |
1 files changed, 30 insertions, 20 deletions
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c index d642c0795452..42e61e10f517 100644 --- a/drivers/gpu/drm/i915/intel_hotplug.c +++ b/drivers/gpu/drm/i915/intel_hotplug.c @@ -114,34 +114,46 @@ 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) { 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 increment = long_hpd ? 10 : 1; const int threshold = hpd->hpd_storm_threshold; bool storm = false; - if (!threshold) + if (!threshold || + (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled)) return false; if (!time_in_range(jiffies, start, end)) { @@ -149,7 +161,8 @@ static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, hpd->stats[pin].count = 0; } - if (++hpd->stats[pin].count > threshold) { + 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; @@ -409,28 +422,24 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, for_each_intel_encoder(&dev_priv->drm, encoder) { enum hpd_pin pin = encoder->hpd_pin; bool has_hpd_pulse = intel_encoder_has_hpd_pulse(encoder); + bool long_hpd = true; if (!(BIT(pin) & pin_mask)) continue; if (has_hpd_pulse) { - bool long_hpd = long_mask & BIT(pin); enum port port = encoder->port; + long_hpd = long_mask & BIT(pin); + DRM_DEBUG_DRIVER("digital hpd port %c - %s\n", port_name(port), long_hpd ? "long" : "short"); - /* - * For long HPD pulses we want to have the digital queue happen, - * but we still want HPD storm detection to function. - */ queue_dig = true; - if (long_hpd) { + if (long_hpd) dev_priv->hotplug.long_port_mask |= (1 << port); - } else { - /* for short HPD just trigger the digital queue */ + else dev_priv->hotplug.short_port_mask |= (1 << port); - continue; - } + } if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED) { @@ -453,9 +462,10 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, queue_hp = true; } - 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; } } |