2 files changed, 32 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 738a4294d820..f6829ba58e86 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -122,6 +122,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
         int count = 0;
         int mode_flags = 0;
         bool verbose_prune = true;
+        enum drm_connector_status old_status;
 
         DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
                         drm_get_connector_name(connector));
@@ -137,7 +138,32 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
                 if (connector->funcs->force)
                         connector->funcs->force(connector);
         } else {
+                old_status = connector->status;
+
                 connector->status = connector->funcs->detect(connector, true);
+
+                /*
+                 * Normally either the driver's hpd code or the poll loop should
+                 * pick up any changes and fire the hotplug event. But if
+                 * userspace sneaks in a probe, we might miss a change. Hence
+                 * check here, and if anything changed start the hotplug code.
+                 */
+                if (old_status != connector->status) {
+                        DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
+                                      connector->base.id,
+                                      drm_get_connector_name(connector),
+                                      old_status, connector->status);
+
+                        /*
+                         * The hotplug event code might call into the fb
+                         * helpers, and so expects that we do not hold any
+                         * locks. Fire up the poll struct instead, it will
+                         * disable itself again.
+                         */
+                        dev->mode_config.delayed_event = true;
+                        schedule_delayed_work(&dev->mode_config.output_poll_work,
+                                              0);
+                }
         }
 
         /* Re-enable polling in case the global poll config changed. */
@@ -985,7 +1011,11 @@ static void output_poll_execute(struct work_struct *work)
         struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
         struct drm_connector *connector;
         enum drm_connector_status old_status;
-        bool repoll = false, changed = false;
+        bool repoll = false, changed;
+
+        /* Pick up any changes detected by the probe functions. */
+        changed = dev->mode_config.delayed_event;
+        dev->mode_config.delayed_event = false;
 
         if (!drm_kms_helper_poll)
                 return;
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index b9ddd3d42acf..0fd007af8de9 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -808,6 +808,7 @@ struct drm_mode_config {
         /* output poll support */
         bool poll_enabled;
         bool poll_running;
+        bool delayed_event;
         struct delayed_work output_poll_work;
 
         /* pointers to standard properties */