From a2ee48d60eed9cfb6447a4233370aee4ea88108b Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Fri, 29 May 2015 16:14:37 +0300 Subject: [PATCH] drm/i915: abstract hpd irq storm detection Simplify intel_hpd_irq_handler() by extracting HPD irq storm detection to a separate function. Signed-off-by: Jani Nikula Reviewed-by: Paulo Zanoni Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_irq.c | 53 +++++++++++++++++++++++++-------- 1 file changed, 40 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index e4260b0924f1..eb52a039d628 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1375,6 +1375,45 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_i915_private *dev_priv, #define HPD_STORM_DETECT_PERIOD 1000 #define HPD_STORM_THRESHOLD 5 +/** + * intel_hpd_irq_storm - gather stats and detect HPD irq storm on a pin + * @dev_priv: private driver data pointer + * @pin: the pin to gather stats on + * + * 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. + * + * @HPD_STORM_THRESHOLD irqs are allowed within @HPD_STORM_DETECT_PERIOD ms, + * otherwise it's considered an irq storm, and the irq state is set to + * @HPD_MARK_DISABLED. + * + * Return true if an irq storm was detected on @pin. + */ +static bool intel_hpd_irq_storm(struct drm_i915_private *dev_priv, + enum hpd_pin pin) +{ + unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies; + unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD); + bool storm = 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 > HPD_STORM_THRESHOLD) { + dev_priv->hotplug.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); + } + + return storm; +} + static bool pch_port_hotplug_long_detect(enum port port, u32 val) { switch (port) { @@ -1544,21 +1583,9 @@ static void intel_hpd_irq_handler(struct drm_device *dev, queue_hp = true; } - if (!time_in_range(jiffies, dev_priv->hotplug.stats[i].last_jiffies, - dev_priv->hotplug.stats[i].last_jiffies - + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD))) { - dev_priv->hotplug.stats[i].last_jiffies = jiffies; - dev_priv->hotplug.stats[i].count = 0; - DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: 0\n", i); - } else if (dev_priv->hotplug.stats[i].count > HPD_STORM_THRESHOLD) { - dev_priv->hotplug.stats[i].state = HPD_MARK_DISABLED; + if (intel_hpd_irq_storm(dev_priv, i)) { dev_priv->hotplug.event_bits &= ~BIT(i); - DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", i); storm_detected = true; - } else { - dev_priv->hotplug.stats[i].count++; - DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", i, - dev_priv->hotplug.stats[i].count); } } -- 2.30.2