1 files changed, 107 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 45890447feec..a6f73f1e99d9 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -199,6 +199,29 @@ static void drm_helper_add_std_modes(struct drm_device *dev,
 }
 
 /**
+ * drm_helper_encoder_in_use - check if a given encoder is in use
+ * @encoder: encoder to check
+ *
+ * LOCKING:
+ * Caller must hold mode config lock.
+ *
+ * Walk @encoders's DRM device's mode_config and see if it's in use.
+ *
+ * RETURNS:
+ * True if @encoder is part of the mode_config, false otherwise.
+ */
+bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
+{
+        struct drm_connector *connector;
+        struct drm_device *dev = encoder->dev;
+        list_for_each_entry(connector, &dev->mode_config.connector_list, head)
+                if (connector->encoder == encoder)
+                        return true;
+        return false;
+}
+EXPORT_SYMBOL(drm_helper_encoder_in_use);
+
+/**
  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
  * @crtc: CRTC to check
  *
@@ -216,7 +239,7 @@ bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
         struct drm_device *dev = crtc->dev;
         /* FIXME: Locking around list access? */
         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
-                if (encoder->crtc == crtc)
+                if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
                         return true;
         return false;
 }
@@ -240,7 +263,7 @@ void drm_helper_disable_unused_functions(struct drm_device *dev)
 
         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
                 encoder_funcs = encoder->helper_private;
-                if (!encoder->crtc)
+                if (!drm_helper_encoder_in_use(encoder))
                         (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
         }
 
@@ -935,6 +958,88 @@ bool drm_helper_initial_config(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_helper_initial_config);
 
+static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
+{
+        int dpms = DRM_MODE_DPMS_OFF;
+        struct drm_connector *connector;
+        struct drm_device *dev = encoder->dev;
+
+        list_for_each_entry(connector, &dev->mode_config.connector_list, head)
+                if (connector->encoder == encoder)
+                        if (connector->dpms < dpms)
+                                dpms = connector->dpms;
+        return dpms;
+}
+
+static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
+{
+        int dpms = DRM_MODE_DPMS_OFF;
+        struct drm_connector *connector;
+        struct drm_device *dev = crtc->dev;
+
+        list_for_each_entry(connector, &dev->mode_config.connector_list, head)
+                if (connector->encoder && connector->encoder->crtc == crtc)
+                        if (connector->dpms < dpms)
+                                dpms = connector->dpms;
+        return dpms;
+}
+
+/**
+ * drm_helper_connector_dpms
+ * @connector affected connector
+ * @mode DPMS mode
+ *
+ * Calls the low-level connector DPMS function, then
+ * calls appropriate encoder and crtc DPMS functions as well
+ */
+void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
+{
+        struct drm_encoder *encoder = connector->encoder;
+        struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
+        int old_dpms;
+
+        if (mode == connector->dpms)
+                return;
+
+        old_dpms = connector->dpms;
+        connector->dpms = mode;
+
+        /* from off to on, do crtc then encoder */
+        if (mode < old_dpms) {
+                if (crtc) {
+                        struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
+                        if (crtc_funcs->dpms)
+                                (*crtc_funcs->dpms) (crtc,
+                                                     drm_helper_choose_crtc_dpms(crtc));
+                }
+                if (encoder) {
+                        struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
+                        if (encoder_funcs->dpms)
+                                (*encoder_funcs->dpms) (encoder,
+                                                        drm_helper_choose_encoder_dpms(encoder));
+                }
+        }
+
+        /* from on to off, do encoder then crtc */
+        if (mode > old_dpms) {
+                if (encoder) {
+                        struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
+                        if (encoder_funcs->dpms)
+                                (*encoder_funcs->dpms) (encoder,
+                                                        drm_helper_choose_encoder_dpms(encoder));
+                }
+                if (crtc) {
+                        struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
+                        if (crtc_funcs->dpms)
+                                (*crtc_funcs->dpms) (crtc,
+                                                     drm_helper_choose_crtc_dpms(crtc));
+                }
+        }
+
+        return;
+}
+EXPORT_SYMBOL(drm_helper_connector_dpms);
+
 /**
  * drm_hotplug_stage_two
  * @dev DRM device