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>
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 4fbb016..fb1bed8 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -445,7 +445,9 @@
* connected and closed means disconnected. We also send hotplug events as
* needed, using lid status notification from the input layer.
*/
-static enum drm_connector_status intel_lvds_detect(struct drm_connector *connector)
+static enum drm_connector_status
+intel_lvds_detect(struct drm_connector *connector,
+ bool nondestructive)
{
struct drm_device *dev = connector->dev;
enum drm_connector_status status = connector_status_connected;
@@ -540,7 +542,9 @@
* the LID nofication event.
*/
if (connector)
- connector->status = connector->funcs->detect(connector);
+ connector->status = connector->funcs->detect(connector,
+ true);
+
/* Don't force modeset on machines where it causes a GPU lockup */
if (dmi_check_system(intel_no_modeset_on_lid))
return NOTIFY_OK;