From 32a68695d44af37408a8a6578821864478421581 Mon Sep 17 00:00:00 2001
From: Ray Strode <rstrode@redhat.com>
Date: Mon, 21 Sep 2009 11:33:24 -0400
Subject: [PATCH] [drm] Find unused encoder if none used

Apparently, we can end up in situations where an encoder
isn't yet assigned to a connector.  In those cases, we
pick one of the available encoders and use it.
---
 src/plugins/renderers/drm/plugin.c |   60 ++++++++++++++++++++++++++++++++++-
 1 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/src/plugins/renderers/drm/plugin.c b/src/plugins/renderers/drm/plugin.c
index 7c8520b..6af8f35 100644
--- a/src/plugins/renderers/drm/plugin.c
+++ b/src/plugins/renderers/drm/plugin.c
@@ -77,6 +77,7 @@ struct _ply_renderer_head
   drmModeModeInfo *mode;
 
   uint32_t controller_id;
+  uint32_t encoder_id;
   uint32_t scan_out_buffer_id;
 };
 
@@ -116,6 +117,7 @@ ply_renderer_plugin_interface_t *ply_renderer_backend_get_interface (void);
 static ply_renderer_head_t *
 ply_renderer_head_new (ply_renderer_backend_t *backend,
                        drmModeConnector       *connector,
+                       uint32_t                encoder_id,
                        uint32_t                controller_id,
                        drmModeModeInfo        *mode)
 {
@@ -125,6 +127,7 @@ ply_renderer_head_new (ply_renderer_backend_t *backend,
 
   head->backend = backend;
   head->connector = connector;
+  head->encoder_id = encoder_id;
   head->controller_id = controller_id;
   head->mode = mode;
 
@@ -531,6 +534,54 @@ find_controller_for_encoder (ply_renderer_backend_t *backend,
   return 0;
 }
 
+static bool
+encoder_is_available (ply_renderer_backend_t *backend,
+                      uint32_t                encoder_id)
+{
+  ply_list_node_t *node;
+
+  node = ply_list_get_first_node (backend->heads);
+  while (node != NULL)
+    {
+      ply_list_node_t *next_node;
+      ply_renderer_head_t *head;
+
+      head = (ply_renderer_head_t *) ply_list_node_get_data (node);
+      next_node = ply_list_get_next_node (backend->heads, node);
+
+      if (head->encoder_id == encoder_id)
+        return false;
+
+      node = next_node;
+    }
+
+  return true;
+}
+
+static drmModeEncoder *
+find_unused_encoder_for_connector (ply_renderer_backend_t *backend,
+                                   drmModeConnector       *connector)
+{
+  int i;
+  drmModeEncoder *encoder;
+
+  for (i = 0; i < connector->count_encoders; i++)
+    {
+      encoder = drmModeGetEncoder (backend->device_fd,
+                                   connector->encoders[i]);
+
+      if (encoder == NULL)
+        continue;
+
+      if (encoder_is_available (backend, encoder->encoder_id))
+        return encoder;
+
+      drmModeFreeEncoder (encoder);
+    }
+
+  return NULL;
+}
+
 static drmModeEncoder *
 find_encoder_for_connector (ply_renderer_backend_t *backend,
                             drmModeConnector       *connector)
@@ -554,7 +605,9 @@ find_encoder_for_connector (ply_renderer_backend_t *backend,
       drmModeFreeEncoder (encoder);
     }
 
-  return NULL;
+  /* No encoder yet, pick one
+   */
+  return find_unused_encoder_for_connector (backend, connector);
 }
 
 static bool
@@ -568,6 +621,7 @@ create_heads_for_active_connectors (ply_renderer_backend_t *backend)
       ply_renderer_head_t *head;
       drmModeEncoder *encoder;
       uint32_t controller_id;
+      uint32_t encoder_id;
       drmModeModeInfo *mode;
 
       connector = drmModeGetConnector (backend->device_fd,
@@ -596,6 +650,7 @@ create_heads_for_active_connectors (ply_renderer_backend_t *backend)
           continue;
         }
 
+      encoder_id = encoder->encoder_id;
       controller_id = find_controller_for_encoder (backend, encoder);
       drmModeFreeEncoder (encoder);
 
@@ -607,7 +662,8 @@ create_heads_for_active_connectors (ply_renderer_backend_t *backend)
 
       mode = get_active_mode_for_connector (backend, connector);
 
-      head = ply_renderer_head_new (backend, connector, controller_id, mode);
+      head = ply_renderer_head_new (backend, connector, encoder_id,
+                                    controller_id, mode);
 
       ply_list_append_data (backend->heads, head);
     }
-- 
1.6.4