[PATCH v2] drm: get fbdev size from cmdline mode if it exists

[Vincent Abriou]

In case no connector is found while creating the fbdev, gives the
possibility to specify the default fbdev size by firstly checking if the
command line is defining a preferred mode. Else go into fallback and set
1024x768 fbdev size as it was already done.

Cc: Tomi Valkeinen <tomi.valkeinen at ti.com>
Signed-off-by: Vincent Abriou <vincent.abriou at st.com>
---
Patch v2:
 add a break in the connector for loop when a first cmdline mode is found

 drivers/gpu/drm/drm_fb_helper.c | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 0ab6aaa..b38285f 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1526,6 +1526,7 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 	}
 
 	crtc_count = 0;
+
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		struct drm_display_mode *desired_mode;
 		struct drm_mode_set *mode_set;
@@ -1570,11 +1571,34 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 	}
 
 	if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
-		/* hmm everyone went away - assume VGA cable just fell out
-		   and will come back later. */
-		DRM_INFO("Cannot find any crtc or sizes - going 1024x768\n");
-		sizes.fb_width = sizes.surface_width = 1024;
-		sizes.fb_height = sizes.surface_height = 768;
+		struct drm_display_mode *mode = NULL;
+		/* hmm everyone went away - assume cable just fell out and will
+		 * come back later.
+		 * Get fb size from command line mode (if existing) else fb size
+		 * is set to 1024x768
+		 */
+		for (i = 0; i < fb_helper->connector_count; i++) {
+			struct drm_fb_helper_connector *fb_helper_conn;
+
+			fb_helper_conn = fb_helper->connector_info[i];
+			mode = drm_pick_cmdline_mode(fb_helper_conn);
+			if (mode)
+				break;
+		}
+
+		if (mode) {
+			sizes.fb_width = mode->hdisplay;
+			sizes.fb_height = mode->vdisplay;
+			DRM_INFO("Cannot find any crtc or sizes - use cmdline %dx%d\n",
+				 sizes.fb_width, sizes.fb_height);
+		} else {
+			sizes.fb_width = 1024;
+			sizes.fb_height = 768;
+			DRM_INFO("Cannot find any crtc or sizes - going 1024x768\n");
+		}
+
+		sizes.surface_width = sizes.fb_width;
+		sizes.surface_height = sizes.fb_height;
 	}
 
 	/* push down into drivers */
-- 
2.7.4