drm/i915: Add messages useful for HPD storm detection debugging (v2)
For HPD storm detection we now mask out individual interrupt source
bits. We have already seen a case where HPD interrupt enable bits
were assigned to the wrong pins. To track these conditions more
easily add some debugging messages.
v2: Spelling fixes as suggested by Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Egbert Eich <eich@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index ee3e49c..6a1c207 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -919,6 +919,10 @@
spin_lock(&dev_priv->irq_lock);
for (i = 1; i < HPD_NUM_PINS; i++) {
+ WARN(((hpd[i] & hotplug_trigger) &&
+ dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED),
+ "Received HPD interrupt although disabled\n");
+
if (!(hpd[i] & hotplug_trigger) ||
dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED)
continue;
@@ -929,6 +933,7 @@
+ msecs_to_jiffies(HPD_STORM_DETECT_PERIOD))) {
dev_priv->hpd_stats[i].hpd_last_jiffies = jiffies;
dev_priv->hpd_stats[i].hpd_cnt = 0;
+ DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: 0\n", i);
} else if (dev_priv->hpd_stats[i].hpd_cnt > HPD_STORM_THRESHOLD) {
dev_priv->hpd_stats[i].hpd_mark = HPD_MARK_DISABLED;
dev_priv->hpd_event_bits &= ~(1 << i);
@@ -936,6 +941,8 @@
storm_detected = true;
} else {
dev_priv->hpd_stats[i].hpd_cnt++;
+ DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", i,
+ dev_priv->hpd_stats[i].hpd_cnt);
}
}