From 625b82f2c3a4f7aa1ea90133fbbda854bd3c2f8d Mon Sep 17 00:00:00 2001
From: Ray Strode <rstrode@redhat.com>
Date: Wed, 18 Aug 2010 16:16:35 -0400
Subject: [PATCH] [drm] bail if not in 24bpp color mode

Some server hardware gets initialized into 8bpp mode to
conserve memory.  We can't work in that mode, so we now
check for it and back early.
---
 src/plugins/renderers/drm/plugin.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/src/plugins/renderers/drm/plugin.c b/src/plugins/renderers/drm/plugin.c
index 34a7a389..bf70f97c 100644
--- a/src/plugins/renderers/drm/plugin.c
+++ b/src/plugins/renderers/drm/plugin.c
@@ -766,6 +766,29 @@ get_index_of_active_mode (ply_renderer_backend_t *backend,
   return find_index_of_mode (backend, connector, &controller->mode);
 }
 
+static bool
+buffer_has_reasonable_color_depth (ply_renderer_backend_t *backend,
+                                   uint32_t                buffer_id)
+{
+
+  unsigned int color_depth;
+  bool has_reasonable_color_depth;
+
+  if (!backend->driver_interface->fetch_buffer (backend->driver,
+                                                buffer_id,
+                                                NULL, NULL, NULL, &color_depth))
+    return false;
+
+  if (color_depth == 24 || color_depth == 32)
+    has_reasonable_color_depth = true;
+  else
+    has_reasonable_color_depth = false;
+
+  backend->driver_interface->destroy_buffer (backend->driver, buffer_id);
+
+  return has_reasonable_color_depth;
+}
+
 static bool
 create_heads_for_active_connectors (ply_renderer_backend_t *backend)
 {
@@ -833,6 +856,13 @@ create_heads_for_active_connectors (ply_renderer_backend_t *backend)
       console_buffer_id = controller->buffer_id;
       drmModeFreeCrtc (controller);
 
+      if (!buffer_has_reasonable_color_depth (backend, console_buffer_id))
+        {
+          ply_trace ("frame buffer console doesn't have usable color depth");
+          free_heads (backend);
+          return false;
+        }
+
       head = ply_renderer_head_new (backend, connector, connector_mode_index,
                                     encoder_id, controller_id,
                                     console_buffer_id);