From 8d07cb125c6afc11b6b8c7a97ec848868814b1d6 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 6 Oct 2016 21:07:18 +0100 Subject: [PATCH] i965: Order write of query availablity with earlier writes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Currently we signal the availabilty of the query result using an unordered pipe-control write. As it is unordered, it may be executed before the write of the query result itself - and so an observer may read the query result too early. Fix this by requesting that the write of the availablity flag is ordered after earlier pipe control writes. Testcase: piglit/arb_query_buffer_object-qbo/*async* Signed-off-by: Chris Wilson Reviewed-by: Alejandro Piñeiro --- src/mesa/drivers/dri/i965/gen6_queryobj.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/src/mesa/drivers/dri/i965/gen6_queryobj.c b/src/mesa/drivers/dri/i965/gen6_queryobj.c index cb4f46c28be..a28f83af1d6 100644 --- a/src/mesa/drivers/dri/i965/gen6_queryobj.c +++ b/src/mesa/drivers/dri/i965/gen6_queryobj.c @@ -60,8 +60,17 @@ set_query_availability(struct brw_context *brw, struct brw_query_object *query, */ if (brw->ctx.Extensions.ARB_query_buffer_object && brw_is_query_pipelined(query)) { - brw_emit_pipe_control_write(brw, - PIPE_CONTROL_WRITE_IMMEDIATE, + unsigned flags = PIPE_CONTROL_WRITE_IMMEDIATE; + + if (available) { + /* Order available *after* the query results. */ + flags |= PIPE_CONTROL_FLUSH_ENABLE; + } else { + /* Make it unavailable *before* any pipelined reads. */ + flags |= PIPE_CONTROL_CS_STALL; + } + + brw_emit_pipe_control_write(brw, flags, query->bo, 2 * sizeof(uint64_t), available, 0); } -- 2.30.2