i965: Properly flush in hsw_pause_transform_feedback().

Fixes a number of transform feedback tests when run with Linux 4.8,
which allows us to use the MI_LOAD_REGISTER_REG command, at which point
we started using this new broken path.

ES3-CTS.functional.transform_feedback.array_element.interleaved.lines.*
and Piglit's arb_transform_feedback2/draw-auto are both fixed by this
patch, for example.

Thanks to Chris Wilson for catching this mistake!

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99030
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>

diff --git a/src/mesa/drivers/dri/i965/hsw_sol.c b/src/mesa/drivers/dri/i965/hsw_sol.c
index e299b02270630f06c75c0196bb7ce615baf7a4b3..b0dd150b7df8f39dd3d9a2ce8f62501347951544 100644 (file)
--- a/src/mesa/drivers/dri/i965/hsw_sol.c
+++ b/src/mesa/drivers/dri/i965/hsw_sol.c
@@ -201,6 +201,9 @@ hsw_pause_transform_feedback(struct gl_context *ctx,
       (struct brw_transform_feedback_object *) obj;
 
    if (brw->is_haswell) {
+      /* Flush any drawing so that the counters have the right values. */
+      brw_emit_mi_flush(brw);
+
       /* Save the SOL buffer offset register values. */
       for (int i = 0; i < BRW_MAX_XFB_STREAMS; i++) {
          BEGIN_BATCH(3);