patches.baytrail/0040-drm-i915-Only-reprobe-display-on-encoder-which-has-r.patch

From 8a85a19825edd287c64c597e0b1c51292cd2ceeb Mon Sep 17 00:00:00 2001
From: Egbert Eich <eich@suse.de>
Date: Thu, 11 Apr 2013 16:00:26 +0200
Subject: drm/i915: Only reprobe display on encoder which has received an HPD
 event (v2)

Instead of calling into the DRM helper layer to poll all connectors for
changes in connected displays probe only those connectors which have
received a hotplug event.

v2: Resolved conflicts with changes in previous commits.
    Renamed function and and added a WARN_ON() to warn of
    intel_hpd_irq_event() from being called without
    mode_config.mutex held - suggested by Jani Nikula.

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>
(cherry picked from commit 321a1b3026ea194dd084cf3bda1e235b2986b0af)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 66aa4dacd83f..1d42446e287c 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -532,6 +532,21 @@ static int i915_get_vblank_timestamp(struct drm_device *dev, int pipe,
 						     crtc);
 }
 
+static int intel_hpd_irq_event(struct drm_device *dev, struct drm_connector *connector)
+{
+	enum drm_connector_status old_status;
+
+	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
+	old_status = connector->status;
+
+	connector->status = connector->funcs->detect(connector, false);
+	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
+		      connector->base.id,
+		      drm_get_connector_name(connector),
+		      old_status, connector->status);
+	return (old_status != connector->status);
+}
+
 /*
  * Handle hotplug events outside the interrupt handler proper.
  */
@@ -548,6 +563,7 @@ static void i915_hotplug_work_func(struct work_struct *work)
 	struct drm_connector *connector;
 	unsigned long irqflags;
 	bool hpd_disabled = false;
+	bool changed = false;
 	u32 hpd_event_bits;
 
 	/* HPD irq before everything is fully set up. */
@@ -591,14 +607,20 @@ static void i915_hotplug_work_func(struct work_struct *work)
 
 	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
 
-	list_for_each_entry(intel_encoder, &mode_config->encoder_list, base.head)
-		if (intel_encoder->hot_plug)
-			intel_encoder->hot_plug(intel_encoder);
-
+	list_for_each_entry(connector, &mode_config->connector_list, head) {
+		intel_connector = to_intel_connector(connector);
+		intel_encoder = intel_connector->encoder;
+		if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) {
+			if (intel_encoder->hot_plug)
+				intel_encoder->hot_plug(intel_encoder);
+			if (intel_hpd_irq_event(dev, connector))
+				changed = true;
+		}
+	}
 	mutex_unlock(&mode_config->mutex);
 
-	/* Just fire off a uevent and let userspace tell us what to do */
-	drm_helper_hpd_irq_event(dev);
+	if (changed)
+		drm_kms_helper_hotplug_event(dev);
 }
 
 static void ironlake_handle_rps_change(struct drm_device *dev)
-- 
1.8.5.rc3