Revert "drm/i915: Check live status before reading edid"

This reverts commit 237ed86c693d8a8e4db476976aeb30df4deac74b.

Our current implementation of live status check (repeat 9 times
with 10ms delays between each attempt as a workaround for
buggy displays) imposes a rather serious penalty, time wise,
on intel_hdmi_detect().  Since we we already skip live status
checks on platforms before gen 7, and since we seem to have
coped quite well before the live status check was introduced
for newer platforms too, the previous behaviour is probably
preferable, at least unless someone can point to a use-case
that the live status check improves (apart from "Bspec says so".)

Signed-off-by: David Weinehall <david.weinehall@linux.intel.com>
Fixes: 237ed86c693d ("drm/i915: Check live status before reading edid")
Fixes: f8d03ea0053b ("drm/i915: increase the tries for HDMI hotplug live status checking")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97139
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94014
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160817124748.31208-1-david.weinehall@linux.intel.com

1 files changed, 10 insertions, 33 deletions

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 1a116a6a1817..c51073f78730 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1439,24 +1439,22 @@ intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector, bool has_edid)
 }
 
 static bool
-intel_hdmi_set_edid(struct drm_connector *connector, bool force)
+intel_hdmi_set_edid(struct drm_connector *connector)
 {
 	struct drm_i915_private *dev_priv = to_i915(connector->dev);
 	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
-	struct edid *edid = NULL;
+	struct edid *edid;
 	bool connected = false;
 
-	if (force) {
-		intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
+	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
 
-		edid = drm_get_edid(connector,
-				    intel_gmbus_get_adapter(dev_priv,
-				    intel_hdmi->ddc_bus));
+	edid = drm_get_edid(connector,
+			    intel_gmbus_get_adapter(dev_priv,
+			    intel_hdmi->ddc_bus));
 
-		intel_hdmi_dp_dual_mode_detect(connector, edid != NULL);
+	intel_hdmi_dp_dual_mode_detect(connector, edid != NULL);
 
-		intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
-	}
+	intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
 
 	to_intel_connector(connector)->detect_edid = edid;
 	if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {
@@ -1482,37 +1480,16 @@ static enum drm_connector_status
 intel_hdmi_detect(struct drm_connector *connector, bool force)
 {
 	enum drm_connector_status status;
-	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
 	struct drm_i915_private *dev_priv = to_i915(connector->dev);
-	bool live_status = false;
-	unsigned int try;
 
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
 		      connector->base.id, connector->name);
 
 	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
 
-	for (try = 0; !live_status && try < 9; try++) {
-		if (try)
-			msleep(10);
-		live_status = intel_digital_port_connected(dev_priv,
-				hdmi_to_dig_port(intel_hdmi));
-	}
-
-	if (!live_status) {
-		DRM_DEBUG_KMS("HDMI live status down\n");
-		/*
-		 * Live status register is not reliable on all intel platforms.
-		 * So consider live_status only for certain platforms, for
-		 * others, read EDID to determine presence of sink.
-		 */
-		if (INTEL_INFO(dev_priv)->gen < 7 || IS_IVYBRIDGE(dev_priv))
-			live_status = true;
-	}
-
 	intel_hdmi_unset_edid(connector);
 
-	if (intel_hdmi_set_edid(connector, live_status)) {
+	if (intel_hdmi_set_edid(connector)) {
 		struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
 
 		hdmi_to_dig_port(intel_hdmi)->base.type = INTEL_OUTPUT_HDMI;
@@ -1538,7 +1515,7 @@ intel_hdmi_force(struct drm_connector *connector)
 	if (connector->status != connector_status_connected)
 		return;
 
-	intel_hdmi_set_edid(connector, true);
+	intel_hdmi_set_edid(connector);
 	hdmi_to_dig_port(intel_hdmi)->base.type = INTEL_OUTPUT_HDMI;
 }