1 files changed, 100 insertions, 76 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index d5d8cea1a67..0c0c39bac23 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -49,10 +49,11 @@ static LIST_HEAD(kernel_fb_helper_list);
  * helper functions used by many drivers to implement the kernel mode setting
  * interfaces.
  *
- * Initialization is done as a three-step process with drm_fb_helper_init(),
- * drm_fb_helper_single_add_all_connectors() and drm_fb_helper_initial_config().
- * Drivers with fancier requirements than the default behaviour can override the
- * second step with their own code.  Teardown is done with drm_fb_helper_fini().
+ * Initialization is done as a four-step process with drm_fb_helper_prepare(),
+ * drm_fb_helper_init(), drm_fb_helper_single_add_all_connectors() and
+ * drm_fb_helper_initial_config(). Drivers with fancier requirements than the
+ * default behaviour can override the third step with their own code.
+ * Teardown is done with drm_fb_helper_fini().
  *
  * At runtime drivers should restore the fbdev console by calling
  * drm_fb_helper_restore_fbdev_mode() from their ->lastclose callback. They
@@ -63,6 +64,19 @@ static LIST_HEAD(kernel_fb_helper_list);
  *
  * All other functions exported by the fb helper library can be used to
  * implement the fbdev driver interface by the driver.
+ *
+ * It is possible, though perhaps somewhat tricky, to implement race-free
+ * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
+ * helper must be called first to initialize the minimum required to make
+ * hotplug detection work. Drivers also need to make sure to properly set up
+ * the dev->mode_config.funcs member. After calling drm_kms_helper_poll_init()
+ * it is safe to enable interrupts and start processing hotplug events. At the
+ * same time, drivers should initialize all modeset objects such as CRTCs,
+ * encoders and connectors. To finish up the fbdev helper initialization, the
+ * drm_fb_helper_init() function is called. To probe for all attached displays
+ * and set up an initial configuration using the detected hardware, drivers
+ * should call drm_fb_helper_single_add_all_connectors() followed by
+ * drm_fb_helper_initial_config().
  */
 
 /**
@@ -105,59 +119,57 @@ fail:
 }
 EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);
 
-static int drm_fb_helper_parse_command_line(struct drm_fb_helper *fb_helper)
+int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector)
 {
-	struct drm_fb_helper_connector *fb_helper_conn;
-	int i;
+	struct drm_fb_helper_connector **temp;
+	struct drm_fb_helper_connector *fb_helper_connector;
 
-	for (i = 0; i < fb_helper->connector_count; i++) {
-		struct drm_cmdline_mode *mode;
-		struct drm_connector *connector;
-		char *option = NULL;
+	WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
+	if (fb_helper->connector_count + 1 > fb_helper->connector_info_alloc_count) {
+		temp = krealloc(fb_helper->connector_info, sizeof(struct drm_fb_helper_connector *) * (fb_helper->connector_count + 1), GFP_KERNEL);
+		if (!temp)
+			return -ENOMEM;
 
-		fb_helper_conn = fb_helper->connector_info[i];
-		connector = fb_helper_conn->connector;
-		mode = &fb_helper_conn->cmdline_mode;
+		fb_helper->connector_info_alloc_count = fb_helper->connector_count + 1;
+		fb_helper->connector_info = temp;
+	}
 
-		/* do something on return - turn off connector maybe */
-		if (fb_get_options(connector->name, &option))
-			continue;
 
-		if (drm_mode_parse_command_line_for_connector(option,
-							      connector,
-							      mode)) {
-			if (mode->force) {
-				const char *s;
-				switch (mode->force) {
-				case DRM_FORCE_OFF:
-					s = "OFF";
-					break;
-				case DRM_FORCE_ON_DIGITAL:
-					s = "ON - dig";
-					break;
-				default:
-				case DRM_FORCE_ON:
-					s = "ON";
-					break;
-				}
-
-				DRM_INFO("forcing %s connector %s\n",
-					 connector->name, s);
-				connector->force = mode->force;
-			}
+	fb_helper_connector = kzalloc(sizeof(struct drm_fb_helper_connector), GFP_KERNEL);
+	if (!fb_helper_connector)
+		return -ENOMEM;
 
-			DRM_DEBUG_KMS("cmdline mode for connector %s %dx%d@%dHz%s%s%s\n",
-				      connector->name,
-				      mode->xres, mode->yres,
-				      mode->refresh_specified ? mode->refresh : 60,
-				      mode->rb ? " reduced blanking" : "",
-				      mode->margins ? " with margins" : "",
-				      mode->interlace ?  " interlaced" : "");
-		}
+	fb_helper_connector->connector = connector;
+	fb_helper->connector_info[fb_helper->connector_count++] = fb_helper_connector;
+	return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_add_one_connector);
+
+int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
+				       struct drm_connector *connector)
+{
+	struct drm_fb_helper_connector *fb_helper_connector;
+	int i, j;
+
+	WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
+
+	for (i = 0; i < fb_helper->connector_count; i++) {
+		if (fb_helper->connector_info[i]->connector == connector)
+			break;
+	}
+
+	if (i == fb_helper->connector_count)
+		return -EINVAL;
+	fb_helper_connector = fb_helper->connector_info[i];
 
+	for (j = i + 1; j < fb_helper->connector_count; j++) {
+		fb_helper->connector_info[j - 1] = fb_helper->connector_info[j];
 	}
+	fb_helper->connector_count--;
+	kfree(fb_helper_connector);
 	return 0;
 }
+EXPORT_SYMBOL(drm_fb_helper_remove_one_connector);
 
 static void drm_fb_helper_save_lut_atomic(struct drm_crtc *crtc, struct drm_fb_helper *helper)
 {
@@ -199,9 +211,6 @@ int drm_fb_helper_debug_enter(struct fb_info *info)
 	struct drm_crtc_helper_funcs *funcs;
 	int i;
 
-	if (list_empty(&kernel_fb_helper_list))
-		return false;
-
 	list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
 		for (i = 0; i < helper->crtc_count; i++) {
 			struct drm_mode_set *mode_set =
@@ -282,10 +291,17 @@ static bool restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 
 	drm_warn_on_modeset_not_all_locked(dev);
 
-	list_for_each_entry(plane, &dev->mode_config.plane_list, head)
+	list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
 		if (plane->type != DRM_PLANE_TYPE_PRIMARY)
 			drm_plane_force_disable(plane);
 
+		if (dev->mode_config.rotation_property) {
+			drm_mode_plane_set_obj_prop(plane,
+						    dev->mode_config.rotation_property,
+						    BIT(DRM_ROTATE_0));
+		}
+	}
+
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
 		struct drm_crtc *crtc = mode_set->crtc;
@@ -356,11 +372,11 @@ static bool drm_fb_helper_force_kernel_mode(void)
 		if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 			continue;
 
-		/* NOTE: we use lockless flag below to avoid grabbing other
-		 * modeset locks.  So just trylock the underlying mutex
-		 * directly:
+		/*
+		 * NOTE: Use trylock mode to avoid deadlocks and sleeping in
+		 * panic context.
 		 */
-		if (!mutex_trylock(&dev->mode_config.mutex)) {
+		if (__drm_modeset_lock_all(dev, true) != 0) {
 			error = true;
 			continue;
 		}
@@ -369,7 +385,7 @@ static bool drm_fb_helper_force_kernel_mode(void)
 		if (ret)
 			error = true;
 
-		mutex_unlock(&dev->mode_config.mutex);
+		drm_modeset_unlock_all(dev);
 	}
 	return error;
 }
@@ -531,6 +547,24 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
 }
 
 /**
+ * drm_fb_helper_prepare - setup a drm_fb_helper structure
+ * @dev: DRM device
+ * @helper: driver-allocated fbdev helper structure to set up
+ * @funcs: pointer to structure of functions associate with this helper
+ *
+ * Sets up the bare minimum to make the framebuffer helper usable. This is
+ * useful to implement race-free initialization of the polling helpers.
+ */
+void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
+			   const struct drm_fb_helper_funcs *funcs)
+{
+	INIT_LIST_HEAD(&helper->kernel_fb_list);
+	helper->funcs = funcs;
+	helper->dev = dev;
+}
+EXPORT_SYMBOL(drm_fb_helper_prepare);
+
+/**
  * drm_fb_helper_init - initialize a drm_fb_helper structure
  * @dev: drm device
  * @fb_helper: driver-allocated fbdev helper structure to initialize
@@ -542,8 +576,7 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
  * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
  * to allow driver writes more control over the exact init sequence.
  *
- * Drivers must set fb_helper->funcs before calling
- * drm_fb_helper_initial_config().
+ * Drivers must call drm_fb_helper_prepare() before calling this function.
  *
  * RETURNS:
  * Zero if everything went ok, nonzero otherwise.
@@ -558,10 +591,6 @@ int drm_fb_helper_init(struct drm_device *dev,
 	if (!max_conn_count)
 		return -EINVAL;
 
-	fb_helper->dev = dev;
-
-	INIT_LIST_HEAD(&fb_helper->kernel_fb_list);
-
 	fb_helper->crtc_info = kcalloc(crtc_count, sizeof(struct drm_fb_helper_crtc), GFP_KERNEL);
 	if (!fb_helper->crtc_info)
 		return -ENOMEM;
@@ -572,6 +601,7 @@ int drm_fb_helper_init(struct drm_device *dev,
 		kfree(fb_helper->crtc_info);
 		return -ENOMEM;
 	}
+	fb_helper->connector_info_alloc_count = dev->mode_config.num_connector;
 	fb_helper->connector_count = 0;
 
 	for (i = 0; i < crtc_count; i++) {
@@ -936,7 +966,7 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 		struct drm_fb_helper_connector *fb_helper_conn = fb_helper->connector_info[i];
 		struct drm_cmdline_mode *cmdline_mode;
 
-		cmdline_mode = &fb_helper_conn->cmdline_mode;
+		cmdline_mode = &fb_helper_conn->connector->cmdline_mode;
 
 		if (cmdline_mode->bpp_specified) {
 			switch (cmdline_mode->bpp) {
@@ -1056,7 +1086,6 @@ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
 	info->fix.ypanstep = 1; /* doing it in hw */
 	info->fix.ywrapstep = 0;
 	info->fix.accel = FB_ACCEL_NONE;
-	info->fix.type_aux = 0;
 
 	info->fix.line_length = pitch;
 	return;
@@ -1184,9 +1213,7 @@ EXPORT_SYMBOL(drm_has_preferred_mode);
 
 static bool drm_has_cmdline_mode(struct drm_fb_helper_connector *fb_connector)
 {
-	struct drm_cmdline_mode *cmdline_mode;
-	cmdline_mode = &fb_connector->cmdline_mode;
-	return cmdline_mode->specified;
+	return fb_connector->connector->cmdline_mode.specified;
 }
 
 struct drm_display_mode *drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
@@ -1196,7 +1223,7 @@ struct drm_display_mode *drm_pick_cmdline_mode(struct drm_fb_helper_connector *f
 	struct drm_display_mode *mode = NULL;
 	bool prefer_non_interlace;
 
-	cmdline_mode = &fb_helper_conn->cmdline_mode;
+	cmdline_mode = &fb_helper_conn->connector->cmdline_mode;
 	if (cmdline_mode->specified == false)
 		return mode;
 
@@ -1581,8 +1608,6 @@ bool drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
 	struct drm_device *dev = fb_helper->dev;
 	int count = 0;
 
-	drm_fb_helper_parse_command_line(fb_helper);
-
 	mutex_lock(&dev->mode_config.mutex);
 	count = drm_fb_helper_probe_connector_modes(fb_helper,
 						    dev->mode_config.max_width,
@@ -1613,8 +1638,10 @@ EXPORT_SYMBOL(drm_fb_helper_initial_config);
  * either the output polling work or a work item launched from the driver's
  * hotplug interrupt).
  *
- * Note that the driver must ensure that this is only called _after_ the fb has
- * been fully set up, i.e. after the call to drm_fb_helper_initial_config.
+ * Note that drivers may call this even before calling
+ * drm_fb_helper_initial_config but only aftert drm_fb_helper_init. This allows
+ * for a race-free fbcon setup and will make sure that the fbdev emulation will
+ * not miss any hotplug events.
  *
  * RETURNS:
  * 0 on success and a non-zero error code otherwise.
@@ -1624,11 +1651,8 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
 	struct drm_device *dev = fb_helper->dev;
 	u32 max_width, max_height;
 
-	if (!fb_helper->fb)
-		return 0;
-
 	mutex_lock(&fb_helper->dev->mode_config.mutex);
-	if (!drm_fb_helper_is_bound(fb_helper)) {
+	if (!fb_helper->fb || !drm_fb_helper_is_bound(fb_helper)) {
 		fb_helper->delayed_hotplug = true;
 		mutex_unlock(&fb_helper->dev->mode_config.mutex);
 		return 0;