drm/i915: Don't WARN nor handle unexpected hpd interrupts on gmch platforms
The status bits are unconditionally set, the control bits only enable
the actual interrupt generation. Which means if we get some random
other interrupts we'll bogusly complain about them.
So restrict the WARN to platforms with a sane hotplug interrupt
handling scheme. And even more important also don't attempt to process
the hpd bit since we've detected a storm already. Instead just clear
the bit silently.
This WARN has been introduced in
commit b8f102e8bf71cacf33326360fdf9dcfd1a63925b
Author: Egbert Eich <eich@suse.de>
Date: Fri Jul 26 14:14:24 2013 +0200
drm/i915: Add messages useful for HPD storm detection debugging (v2)
before that we silently handled the hpd event and so partially
defeated the storm detection.
v2: Pimp commit message (Jani)
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Egbert Eich <eich@suse.de>
Cc: bitlord <bitlord0xff@gmail.com>
Reported-by: bitlord <bitlord0xff@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 7753249..f98ba4e 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1362,10 +1362,20 @@
spin_lock(&dev_priv->irq_lock);
for (i = 1; i < HPD_NUM_PINS; i++) {
- WARN_ONCE(hpd[i] & hotplug_trigger &&
- dev_priv->hpd_stats[i].hpd_mark == HPD_DISABLED,
- "Received HPD interrupt (0x%08x) on pin %d (0x%08x) although disabled\n",
- hotplug_trigger, i, hpd[i]);
+ if (hpd[i] & hotplug_trigger &&
+ dev_priv->hpd_stats[i].hpd_mark == HPD_DISABLED) {
+ /*
+ * On GMCH platforms the interrupt mask bits only
+ * prevent irq generation, not the setting of the
+ * hotplug bits itself. So only WARN about unexpected
+ * interrupts on saner platforms.
+ */
+ WARN_ONCE(INTEL_INFO(dev)->gen >= 5 && !IS_VALLEYVIEW(dev),
+ "Received HPD interrupt (0x%08x) on pin %d (0x%08x) although disabled\n",
+ hotplug_trigger, i, hpd[i]);
+
+ continue;
+ }
if (!(hpd[i] & hotplug_trigger) ||
dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED)