From 991a3999908f460c3ae1ee4a9e20fc2013bbb85b Mon Sep 17 00:00:00 2001
From: David Lechner <david@lechnology.com>
Date: Fri, 4 Aug 2017 11:25:24 -0500
Subject: [PATCH] drm/fb-helper: pass physical dimensions to fbdev
Git-commit: 991a3999908f460c3ae1ee4a9e20fc2013bbb85b
Patch-mainline: v4.14-rc1
References: FATE#322643 bsc#1055900

The fbdev subsystem has a place for physical dimensions (width and height
in mm) that is readable by userspace. Since DRM also knows these
dimensions, pass this information to the fbdev device.

This has to be done in drm_setup_crtcs_fb() instead of drm_setup_crtcs()
because fb_helper->fbdev may be NULL in drm_setup_crtcs().

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1501863924-7154-1-git-send-email-david@lechnology.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/drm_fb_helper.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1882,8 +1882,6 @@ void drm_fb_helper_fill_var(struct fb_in
 	info->var.xoffset = 0;
 	info->var.yoffset = 0;
 	info->var.activate = FB_ACTIVATE_NOW;
-	info->var.height = -1;
-	info->var.width = -1;
 
 	switch (fb->format->depth) {
 	case 8:
@@ -2435,11 +2433,26 @@ out:
  */
 static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
 {
+	struct fb_info *info = fb_helper->fbdev;
 	int i;
 
 	for (i = 0; i < fb_helper->crtc_count; i++)
 		if (fb_helper->crtc_info[i].mode_set.num_connectors)
 			fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
+
+	mutex_lock(&fb_helper->dev->mode_config.mutex);
+	drm_fb_helper_for_each_connector(fb_helper, i) {
+		struct drm_connector *connector =
+					fb_helper->connector_info[i]->connector;
+
+		/* use first connected connector for the physical dimensions */
+		if (connector->status == connector_status_connected) {
+			info->var.width = connector->display_info.width_mm;
+			info->var.height = connector->display_info.height_mm;
+			break;
+		}
+	}
+	mutex_unlock(&fb_helper->dev->mode_config.mutex);
 }
 
 /* Note: Drops fb_helper->lock before returning. */