commit 7b334fcb45b757ffb093696ca3de1b0c8b4a33f1
author Chris Wilson <chris@chris-wilson.co.uk> Thu Sep 09 23:51:02 2010 +0100
committer Dave Airlie <airlied@redhat.com> Mon Sep 13 20:29:11 2010 +1000
tree fe56259639b9f1c993d742e27468087c46e51f05
parent 27849044ca6ff9c52f63271b511282acf6d1c251

drm: Use a nondestructive mode for output detect when polling

Destructive load-detection is very expensive and due to failings
elsewhere can trigger system wide stalls of up to 600ms. A simple
first step to correcting this is not to invoke such an expensive
and destructive load-detection operation automatically.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29536
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=16265
Reported-by: Bruno Prémont <bonbons@linux-vserver.org>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/i915/intel_sdvo.c

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index e3b7a7e..db6b6d4 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1417,7 +1417,7 @@
 	if (!analog_connector)
 		return false;
 
-	if (analog_connector->funcs->detect(analog_connector) ==
+	if (analog_connector->funcs->detect(analog_connector, true) ==
 			connector_status_disconnected)
 		return false;
 
@@ -1486,7 +1486,9 @@
 	return status;
 }
 
-static enum drm_connector_status intel_sdvo_detect(struct drm_connector *connector)
+static enum drm_connector_status
+intel_sdvo_detect(struct drm_connector *connector,
+		  bool nondestructive)
 {
 	uint16_t response;
 	struct drm_encoder *encoder = intel_attached_encoder(connector);