i965/gen7: Skip resetting SOL offsets at batch start with HW contexts.

The software-tracked transform feedback offsets (svbi_0_starting_index)
are incorrect in the presence of primitive restart, so we can't reliably
compute offsets for our buffer pointers after a batch flush.  Thanks to HW
contexts, our transform feedback offsets are now saved, so we can just
keep using the ones from before the batch wrap.

Fixes piglit OpenGL 3.1/primitive-restart-xfb flush
Reviewed-by: Paul Berry <stereotype441@gmail.com>
NOTE: This is a candidate for the 9.1 branch.
This commit is contained in:
Eric Anholt 2013-04-08 10:56:23 -07:00
parent ccf3e8fc9b
commit 62a18da341
2 changed files with 21 additions and 6 deletions

View file

@ -159,6 +159,7 @@ brw_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
struct gl_transform_feedback_object *obj)
{
struct brw_context *brw = brw_context(ctx);
struct intel_context *intel = &brw->intel;
const struct gl_shader_program *vs_prog =
ctx->Shader.CurrentVertexProgram;
const struct gl_transform_feedback_info *linked_xfb_info =
@ -180,6 +181,14 @@ brw_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
brw->sol.svbi_0_starting_index = 0;
brw->sol.svbi_0_max_index = max_index;
brw->sol.offset_0_batch_start = 0;
if (intel->gen >= 7) {
/* Ask the kernel to reset the SO offsets for any previous transform
* feedback, so we start at the start of the user's buffer. (note: these
* are not the query counters)
*/
intel->batch.needs_sol_reset = true;
}
}
void

View file

@ -82,12 +82,14 @@ upload_3dstate_so_buffers(struct brw_context *brw)
end = ALIGN(start + xfb_obj->Size[i], 4);
assert(end <= bo->size);
/* Offset the starting offset by the current vertex index into the
* feedback buffer, offset register is always set to 0 at the start of the
* batchbuffer.
/* If we don't have hardware contexts, then we reset our offsets at the
* start of every batch, so we track the number of vertices written in
* software and increment our pointers by that many.
*/
start += brw->sol.offset_0_batch_start * stride;
assert(start <= end);
if (!intel->hw_ctx) {
start += brw->sol.offset_0_batch_start * stride;
assert(start <= end);
}
BEGIN_BATCH(4);
OUT_BATCH(_3DSTATE_SO_BUFFER << 16 | (4 - 2));
@ -244,7 +246,11 @@ upload_sol_state(struct brw_context *brw)
/* BRW_NEW_VUE_MAP_GEOM_OUT */
upload_3dstate_so_decl_list(brw, &brw->vue_map_geom_out);
intel->batch.needs_sol_reset = true;
/* If we don't have hardware contexts, then some other client may have
* changed the SO write offsets, and we need to rewrite them.
*/
if (!intel->hw_ctx)
intel->batch.needs_sol_reset = true;
}
/* Finally, set up the SOL stage. This command must always follow updates to