Mesa (master): nvc0: reset the instanced elements state when doing blit using 3d engine

[Ilia Mirkin]

Module: Mesa
Branch: master
Commit: 7892210400e8f3bd14697c0a3dd56e98454a45df
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=7892210400e8f3bd14697c0a3dd56e98454a45df

Author: Ilia Mirkin <imirkin at alum.mit.edu>
Date:   Sat May  9 13:25:51 2015 -0400

nvc0: reset the instanced elements state when doing blit using 3d engine

Since we update num_vtxelts here, we could otherwise end up with stale
instancing information in the upper bits which wouldn't otherwise get
reset. (Also we run the risk of the previous draw having set the first
element as instanced.)

This appears as one of the causes for the test pointed out in fdo#90363
to fail on nvc0.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90363
Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: mesa-stable at lists.freedesktop.org

---

 src/gallium/drivers/nouveau/nvc0/nvc0_surface.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_surface.c b/src/gallium/drivers/nouveau/nvc0/nvc0_surface.c
index 4404d8c..a820de7 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_surface.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_surface.c
@@ -1152,6 +1152,12 @@ nvc0_blit_3d(struct nvc0_context *nvc0, const struct pipe_blit_info *info)
                       NVC0_3D_VERTEX_ATTRIB_FORMAT_SIZE_32 |
                       NVC0_3D_VERTEX_ATTRIB_FORMAT_CONST);
    }
+   if (nvc0->state.instance_elts) {
+      nvc0->state.instance_elts = 0;
+      BEGIN_NVC0(push, NVC0_3D(MACRO_VERTEX_ARRAY_PER_INSTANCE), 2);
+      PUSH_DATA (push, n);
+      PUSH_DATA (push, 0);
+   }
    nvc0->state.num_vtxelts = 2;
 
    for (i = 0; i < info->dst.box.depth; ++i, z += dz) {