1 files changed, 73 insertions, 24 deletions

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 7483a47de8e4..6591d48c1b9d 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -58,28 +58,23 @@
 static bool drm_kms_helper_poll = true;
 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
 
-static void drm_mode_validate_flag(struct drm_connector *connector,
-				   int flags)
+static enum drm_mode_status
+drm_mode_validate_flag(const struct drm_display_mode *mode,
+		       int flags)
 {
-	struct drm_display_mode *mode;
+	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
+	    !(flags & DRM_MODE_FLAG_INTERLACE))
+		return MODE_NO_INTERLACE;
 
-	if (flags == (DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_INTERLACE |
-		      DRM_MODE_FLAG_3D_MASK))
-		return;
+	if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
+	    !(flags & DRM_MODE_FLAG_DBLSCAN))
+		return MODE_NO_DBLESCAN;
 
-	list_for_each_entry(mode, &connector->modes, head) {
-		if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
-				!(flags & DRM_MODE_FLAG_INTERLACE))
-			mode->status = MODE_NO_INTERLACE;
-		if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
-				!(flags & DRM_MODE_FLAG_DBLSCAN))
-			mode->status = MODE_NO_DBLESCAN;
-		if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
-				!(flags & DRM_MODE_FLAG_3D_MASK))
-			mode->status = MODE_NO_STEREO;
-	}
+	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
+	    !(flags & DRM_MODE_FLAG_3D_MASK))
+		return MODE_NO_STEREO;
 
-	return;
+	return MODE_OK;
 }
 
 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
@@ -108,6 +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));
 
@@ -126,7 +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. */
@@ -164,18 +186,22 @@ static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connect
 
 	drm_mode_connector_list_update(connector, merge_type_bits);
 
-	if (maxX && maxY)
-		drm_mode_validate_size(dev, &connector->modes, maxX, maxY);
-
 	if (connector->interlace_allowed)
 		mode_flags |= DRM_MODE_FLAG_INTERLACE;
 	if (connector->doublescan_allowed)
 		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
 	if (connector->stereo_allowed)
 		mode_flags |= DRM_MODE_FLAG_3D_MASK;
-	drm_mode_validate_flag(connector, mode_flags);
 
 	list_for_each_entry(mode, &connector->modes, head) {
+		mode->status = drm_mode_validate_basic(mode);
+
+		if (mode->status == MODE_OK)
+			mode->status = drm_mode_validate_size(mode, maxX, maxY);
+
+		if (mode->status == MODE_OK)
+			mode->status = drm_mode_validate_flag(mode, mode_flags);
+
 		if (mode->status == MODE_OK && connector_funcs->mode_valid)
 			mode->status = connector_funcs->mode_valid(connector,
 								   mode);
@@ -275,10 +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) {
@@ -305,6 +335,24 @@ static void output_poll_execute(struct work_struct *work)
 		if (old_status != connector->status) {
 			const char *old, *new;
 
+			/*
+			 * The poll work sets force=false when calling detect so
+			 * that drivers can avoid to do disruptive tests (e.g.
+			 * when load detect cycles could cause flickering on
+			 * other, running displays). This bears the risk that we
+			 * flip-flop between unknown here in the poll work and
+			 * the real state when userspace forces a full detect
+			 * call after receiving a hotplug event due to this
+			 * change.
+			 *
+			 * Hence clamp an unknown detect status to the old
+			 * value.
+			 */
+			if (connector->status == connector_status_unknown) {
+				connector->status = old_status;
+				continue;
+			}
+
 			old = drm_get_connector_status_name(old_status);
 			new = drm_get_connector_status_name(connector->status);
 
@@ -320,6 +368,7 @@ static void output_poll_execute(struct work_struct *work)
 
 	mutex_unlock(&dev->mode_config.mutex);
 
+out:
 	if (changed)
 		drm_kms_helper_hotplug_event(dev);