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>

1 files changed, 15 insertions, 5 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index a9dd7847d96e..31d309a8e75b 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -481,7 +481,9 @@ static int radeon_lvds_mode_valid(struct drm_connector *connector,
         return MODE_OK;
 }
 
-static enum drm_connector_status radeon_lvds_detect(struct drm_connector *connector)
+static enum drm_connector_status
+radeon_lvds_detect(struct drm_connector *connector,
+                   bool nondestructive)
 {
         struct radeon_connector *radeon_connector = to_radeon_connector(connector);
         struct drm_encoder *encoder = radeon_best_single_encoder(connector);
@@ -594,7 +596,9 @@ static int radeon_vga_mode_valid(struct drm_connector *connector,
         return MODE_OK;
 }
 
-static enum drm_connector_status radeon_vga_detect(struct drm_connector *connector)
+static enum drm_connector_status
+radeon_vga_detect(struct drm_connector *connector,
+                  bool nondestructive)
 {
         struct radeon_connector *radeon_connector = to_radeon_connector(connector);
         struct drm_encoder *encoder;
@@ -691,7 +695,9 @@ static int radeon_tv_mode_valid(struct drm_connector *connector,
         return MODE_OK;
 }
 
-static enum drm_connector_status radeon_tv_detect(struct drm_connector *connector)
+static enum drm_connector_status
+radeon_tv_detect(struct drm_connector *connector,
+                 bool nondestructive)
 {
         struct drm_encoder *encoder;
         struct drm_encoder_helper_funcs *encoder_funcs;
@@ -748,7 +754,9 @@ static int radeon_dvi_get_modes(struct drm_connector *connector)
  * we have to check if this analog encoder is shared with anyone else (TV)
  * if its shared we have to set the other connector to disconnected.
  */
-static enum drm_connector_status radeon_dvi_detect(struct drm_connector *connector)
+static enum drm_connector_status
+radeon_dvi_detect(struct drm_connector *connector,
+                  bool nondestructive)
 {
         struct radeon_connector *radeon_connector = to_radeon_connector(connector);
         struct drm_encoder *encoder = NULL;
@@ -972,7 +980,9 @@ static int radeon_dp_get_modes(struct drm_connector *connector)
         return ret;
 }
 
-static enum drm_connector_status radeon_dp_detect(struct drm_connector *connector)
+static enum drm_connector_status
+radeon_dp_detect(struct drm_connector *connector,
+                 bool nondestructive)
 {
         struct radeon_connector *radeon_connector = to_radeon_connector(connector);
         enum drm_connector_status ret = connector_status_disconnected;