1 files changed, 34 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 2fbdcca7ca9a..33bf550a1d3f 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -103,6 +103,7 @@ static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connect
         int count = 0;
         int mode_flags = 0;
         bool verbose_prune = true;
+        enum drm_connector_status old_status;
 
         WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 
@@ -121,7 +122,33 @@ static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connect
                 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,
+                                      connector->name,
+                                      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;
+                        if (dev->mode_config.poll_enabled)
+                                schedule_delayed_work(&dev->mode_config.output_poll_work,
+                                                      0);
+                }
         }
 
         /* Re-enable polling in case the global poll config changed. */
@@ -274,10 +301,14 @@ 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;
+                goto out;
 
         mutex_lock(&dev->mode_config.mutex);
         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
@@ -319,6 +350,7 @@ static void output_poll_execute(struct work_struct *work)
 
         mutex_unlock(&dev->mode_config.mutex);
 
+out:
         if (changed)
                 drm_kms_helper_hotplug_event(dev);