Currently in intel_hpd_irq_storm_detect() when we detect that the last
recorded hotplug wasn't within the period defined by
HPD_STORM_DETECT_DELAY, we make the mistake of resetting the HPD count
to 0 without incrementing it. This results in us only enabling storm
detection when we go +2 above the threshold, e.g. an HPD threshold of 5
would not trigger a storm until we reach a total of 7 hotplugs.
So: rework the code a bit so we reset the HPD count when
HPD_STORM_DETECT_DELAY has passed, then increment the count afterwards.
Also, clean things up a bit to make it easier to undertand.
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_hotplug.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
index 8326900a311e..c11d73de16f2 100644
--- a/drivers/gpu/drm/i915/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/intel_hotplug.c
@@ -135,24 +135,27 @@ enum hpd_pin intel_hpd_pin_default(struct drm_i915_private *dev_priv,
static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv,
enum hpd_pin pin)
{
- 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 threshold = hpd->hpd_storm_threshold;
bool storm = false;
+ if (!threshold)
+ 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;
+ }
+
+ 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;
--
2.19.1
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