i965g: add lots of error checks and early returns

Any allocation that may fail should be checked, and propogate the
error upwards.  At the highest level we will flush batch and retry.

This is an alternate strategy to what the original DRI driver did of
attempting to flush batch from the lowest levels (eg inside
BEGIN_BATCH).  The trouble with that strategy was that flushes could
occur at unexpected times, and additionally there was a need for a
wierd notification mechanism to propogate the 'lost context' state
back up to higher levels.

Propogating the errors directly gives us a lot of flexibility how to
deal with these states, at the expense of a lot more checking in the
code.

Will add some sanity checks later to make sure that out-of-memory
conditions are properly escalated and not lost halfway up the stack.

1 files changed, 42 insertions, 27 deletions

diff --git a/src/gallium/drivers/i965/brw_gs.c b/src/gallium/drivers/i965/brw_gs.c
index 693d8bfdf8d..ce77be24f60 100644
--- a/src/gallium/drivers/i965/brw_gs.c
+++ b/src/gallium/drivers/i965/brw_gs.c
@@ -40,10 +40,12 @@
 
 
 
-static void compile_gs_prog( struct brw_context *brw,
-			     struct brw_gs_prog_key *key )
+static enum pipe_error compile_gs_prog( struct brw_context *brw,
+                                        struct brw_gs_prog_key *key,
+                                        struct brw_winsys_buffer **bo_out )
 {
    struct brw_gs_compile c;
+   enum pipe_error ret;
    const GLuint *program;
    GLuint program_size;
 
@@ -57,9 +59,9 @@ static void compile_gs_prog( struct brw_context *brw,
    c.nr_attrs = c.key.nr_attrs;
 
    if (BRW_IS_IGDNG(brw))
-       c.nr_regs = (c.nr_attrs + 1) / 2 + 3;  /* are vertices packed, or reg-aligned? */
+      c.nr_regs = (c.nr_attrs + 1) / 2 + 3;  /* are vertices packed, or reg-aligned? */
    else
-       c.nr_regs = (c.nr_attrs + 1) / 2 + 1;  /* are vertices packed, or reg-aligned? */
+      c.nr_regs = (c.nr_attrs + 1) / 2 + 1;  /* are vertices packed, or reg-aligned? */
 
    c.nr_bytes = c.nr_regs * REG_SIZE;
 
@@ -93,40 +95,47 @@ static void compile_gs_prog( struct brw_context *brw,
       if (key->hint_gs_always)
 	 brw_gs_lines( &c );
       else {
-	 return;
+	 return PIPE_OK;
       }
       break;
    case PIPE_PRIM_TRIANGLES:
       if (key->hint_gs_always)
 	 brw_gs_tris( &c );
       else {
-	 return;
+	 return PIPE_OK;
       }
       break;
    case PIPE_PRIM_POINTS:
       if (key->hint_gs_always)
 	 brw_gs_points( &c );
       else {
-	 return;
+	 return PIPE_OK;
       }
-      break;      
+      break;
    default:
-      return;
+      assert(0);
+      return PIPE_ERROR_BAD_INPUT;
    }
 
    /* get the program
     */
-   program = brw_get_program(&c.func, &program_size);
+   ret = brw_get_program(&c.func, &program, &program_size);
+   if (ret)
+      return ret;
 
    /* Upload
     */
-   brw->sws->bo_unreference(brw->gs.prog_bo);
-   brw->gs.prog_bo = brw_upload_cache( &brw->cache, BRW_GS_PROG,
-				       &c.key, sizeof(c.key),
-				       NULL, 0,
-				       program, program_size,
-				       &c.prog_data,
-				       &brw->gs.prog_data );
+   ret = brw_upload_cache( &brw->cache, BRW_GS_PROG,
+                           &c.key, sizeof(c.key),
+                           NULL, 0,
+                           program, program_size,
+                           &c.prog_data,
+                           &brw->gs.prog_data,
+                           bo_out );
+   if (ret)
+      return ret;
+
+   return PIPE_OK;
 }
 
 static const unsigned gs_prim[PIPE_PRIM_MAX] = {  
@@ -166,6 +175,8 @@ static void populate_key( struct brw_context *brw,
 static int prepare_gs_prog(struct brw_context *brw)
 {
    struct brw_gs_prog_key key;
+   enum pipe_error ret;
+
    /* Populate the key:
     */
    populate_key(brw, &key);
@@ -175,17 +186,21 @@ static int prepare_gs_prog(struct brw_context *brw)
       brw->gs.prog_active = key.need_gs_prog;
    }
 
-   if (brw->gs.prog_active) {
-      brw->sws->bo_unreference(brw->gs.prog_bo);
-      brw->gs.prog_bo = brw_search_cache(&brw->cache, BRW_GS_PROG,
-					 &key, sizeof(key),
-					 NULL, 0,
-					 &brw->gs.prog_data);
-      if (brw->gs.prog_bo == NULL)
-	 compile_gs_prog( brw, &key );
-   }
+   if (!brw->gs.prog_active)
+      return PIPE_OK;
+
+   if (brw_search_cache(&brw->cache, BRW_GS_PROG,
+                        &key, sizeof(key),
+                        NULL, 0,
+                        &brw->gs.prog_data,
+                        &brw->gs.prog_bo))
+      return PIPE_OK;
+
+   ret = compile_gs_prog( brw, &key, &brw->gs.prog_bo );
+   if (ret)
+      return ret;
 
-   return 0;
+   return PIPE_OK;
 }