[Mesa-dev] [PATCH 2/2] i965: Fix state flagging of Gen6 SOL programs.

[Kenneth Graunke]

It doesn't seem like the old code could possibly work.

1. brw_gs_state_dirty made us bail unless one of these flags were set:
   _NEW_TEXTURE, BRW_NEW_GEOMETRY_PROGRAM, BRW_NEW_TRANSFORM_FEEDBACK
2. If there was no geometry program, we called brw_upload_ff_gs_prog()3
3. That checked brw_ff_gs_state_dirty and bailed unless these were set:
   _NEW_LIGHT, BRW_NEW_PRIMITIVE, BRW_NEW_TRANSFORM_FEEDBACK,
   BRW_NEW_VS_PROG_DATA.
4. brw_ff_gs_prog_key pv_first and attr fields were set based on data
   depending on _NEW_LIGHT and BRW_NEW_VS_PROG_DATA.

This means that if we needed a FF GS program, and changed the VS
outputs or provoking vertex mode, we'd fail to notice that we needed
to emit a new program.
---
 src/mesa/drivers/dri/i965/brw_gs.c           | 16 ----------------
 src/mesa/drivers/dri/i965/brw_state_upload.c |  9 ++++++---
 2 files changed, 6 insertions(+), 19 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_gs.c b/src/mesa/drivers/dri/i965/brw_gs.c
index 9ba94c45c8f..179ccc4c6fb 100644
--- a/src/mesa/drivers/dri/i965/brw_gs.c
+++ b/src/mesa/drivers/dri/i965/brw_gs.c
@@ -206,22 +206,6 @@ brw_upload_gs_prog(struct brw_context *brw)
    if (!brw_gs_state_dirty(brw))
       return;
 
-   if (gp == NULL) {
-      /* No geometry shader.  Vertex data just passes straight through. */
-      if (brw->gen == 6 &&
-          (brw->ctx.NewDriverState & BRW_NEW_TRANSFORM_FEEDBACK)) {
-         brw_upload_ff_gs_prog(brw);
-         return;
-      }
-
-      /* Other state atoms had better not try to access prog_data, since
-       * there's no GS program.
-       */
-      brw->gs.base.prog_data = NULL;
-
-      return;
-   }
-
    brw_gs_populate_key(brw, &key);
 
    if (!brw_search_cache(&brw->cache, BRW_CACHE_GS_PROG,
diff --git a/src/mesa/drivers/dri/i965/brw_state_upload.c b/src/mesa/drivers/dri/i965/brw_state_upload.c
index 1ae45ba2ac1..1608af4f3bd 100644
--- a/src/mesa/drivers/dri/i965/brw_state_upload.c
+++ b/src/mesa/drivers/dri/i965/brw_state_upload.c
@@ -395,10 +395,13 @@ brw_upload_programs(struct brw_context *brw,
       brw_upload_vs_prog(brw);
       brw_upload_tess_programs(brw);
 
-      if (brw->gen < 6)
-         brw_upload_ff_gs_prog(brw);
-      else
+      if (brw->geometry_program) {
          brw_upload_gs_prog(brw);
+      } else {
+         brw->gs.base.prog_data = NULL;
+         if (brw->gen < 7)
+            brw_upload_ff_gs_prog(brw);
+      }
 
       /* Update the VUE map for data exiting the GS stage of the pipeline.
        * This comes from the last enabled shader stage.
-- 
2.14.1