[Mesa-stable] [PATCH] nvc0: fix push hint logic in presence of a start offset

[Ilia Mirkin]

Previously buffer offsets were passed in explicitly as an offset, which
had to be added to the resource address. Now they are passed in via an
increased 'start' parameter. As a result, we were double-adding the
start offset in this kind of situation.

This condition was triggered by piglit's draw-elements test which has a
requisite glMultiDrawElements in combination with a small enough number
of vertices to go through the immediate push path.

Reported-by: Karol Herbst <karolherbst at gmail.com>
Fixes: 330d0607ed6 ("gallium: remove pipe_index_buffer and set_index_buffer")
Cc: mesa-stable at lists.freedesktop.org
---
 src/gallium/drivers/nouveau/nvc0/nvc0_vbo_translate.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_vbo_translate.c b/src/gallium/drivers/nouveau/nvc0/nvc0_vbo_translate.c
index f05618f6596..256e20df2e4 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_vbo_translate.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_vbo_translate.c
@@ -84,13 +84,12 @@ nvc0_vertex_configure_translate(struct nvc0_context *nvc0, int32_t index_bias)
 
 static inline void
 nvc0_push_map_idxbuf(struct push_context *ctx, struct nvc0_context *nvc0,
-                     const struct pipe_draw_info *info,
-                     unsigned offset)
+                     const struct pipe_draw_info *info)
 {
    if (!info->has_user_indices) {
       struct nv04_resource *buf = nv04_resource(info->index.resource);
-      ctx->idxbuf = nouveau_resource_map_offset(&nvc0->base,
-         buf, offset, NOUVEAU_BO_RD);
+      ctx->idxbuf = nouveau_resource_map_offset(
+            &nvc0->base, buf, 0, NOUVEAU_BO_RD);
    } else {
       ctx->idxbuf = info->index.user;
    }
@@ -509,7 +508,7 @@ nvc0_push_vbo(struct nvc0_context *nvc0, const struct pipe_draw_info *info)
    nvc0->state.prim_restart = info->primitive_restart;
 
    if (info->index_size) {
-      nvc0_push_map_idxbuf(&ctx, nvc0, info, info->start * info->index_size);
+      nvc0_push_map_idxbuf(&ctx, nvc0, info);
       index_size = info->index_size;
    } else {
       if (unlikely(info->count_from_stream_output)) {
-- 
2.13.6