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>
This commit is contained in:
Egbert Eich 2013-07-26 14:14:24 +02:00 committed by Daniel Vetter
parent 3b27af3560
commit b8f102e8bf
1 changed files with 7 additions and 0 deletions

View File

@ -919,6 +919,10 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
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 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
+ 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 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
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);
}
}