drm/i915/vlv: Disable HPD in valleyview_crt_detect_hotplug()
One of the things preventing us from using polling is the fact that
calling valleyview_crt_detect_hotplug() when there's a VGA cable
connected results in sending another hotplug. With polling enabled when
HPD is disabled, this results in a scenario like this:
- We enable power wells and reset the ADPA
- output_poll_exec does force probe on VGA, triggering a hpd
- HPD handler waits for poll to unlock dev->mode_config.mutex
- output_poll_exec shuts off the ADPA, unlocks dev->mode_config.mutex
- HPD handler runs, resets ADPA and brings us back to the start
This results in an endless irq storm getting sent from the ADPA
whenever a VGA connector gets detected in the middle of polling.
Somewhat based off of the "drm/i915: Disable CRT HPD around force
trigger" patch Ville Syrjälä sent a while back
Cc: stable@vger.kernel.org
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Lyude <cpaul@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
index 51434ec..57f50a1 100644
--- a/drivers/gpu/drm/i915/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/intel_hotplug.c
@@ -510,3 +510,30 @@
cancel_work_sync(&dev_priv->hotplug.hotplug_work);
cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);
}
+
+bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
+{
+ bool ret = false;
+
+ if (pin == HPD_NONE)
+ return false;
+
+ spin_lock_irq(&dev_priv->irq_lock);
+ if (dev_priv->hotplug.stats[pin].state == HPD_ENABLED) {
+ dev_priv->hotplug.stats[pin].state = HPD_DISABLED;
+ ret = true;
+ }
+ spin_unlock_irq(&dev_priv->irq_lock);
+
+ return ret;
+}
+
+void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
+{
+ if (pin == HPD_NONE)
+ return;
+
+ spin_lock_irq(&dev_priv->irq_lock);
+ dev_priv->hotplug.stats[pin].state = HPD_ENABLED;
+ spin_unlock_irq(&dev_priv->irq_lock);
+}