[Mesa-dev] [PATCH] radeon: only suspend queries on flush if they haven't been suspended yet

[Nicolai Hähnle]

From: Nicolai Hähnle <nicolai.haehnle at amd.com>

Non-timer queries are suspended during blits. When the blits end, the queries
are resumed, but this resume operation itself might run out of CS space and
trigger a flush. When this happens, we must prevent a duplicate suspend during
preflush suspend, and we must also prevent a duplicate resume when the CS flush
returns back to the original resume operation.

This fixes a regression that was introduced by:

commit 8a125afa6e88a3eeddba8c7fdc1a75c9b99d5489
Author: Nicolai Hähnle <nhaehnle at gmail.com>
Date:   Wed Nov 18 18:40:22 2015 +0100

    radeon: ensure that timing/profiling queries are suspended on flush

    The queries_suspended_for_flush flag is redundant because suspended queries
    are not removed from their respective linked list.

    Reviewed-by: Marek Olšák <marek.olsak at amd.com>

Reported-by: Axel Davy <axel.davy at ens.fr>
Cc: "11.1" <mesa-stable at lists.freedesktop.org>
---
 src/gallium/drivers/radeon/r600_pipe_common.c | 10 ++++++++--
 src/gallium/drivers/radeon/r600_pipe_common.h |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/radeon/r600_pipe_common.c b/src/gallium/drivers/radeon/r600_pipe_common.c
index f03dcd9..aaea8fe 100644
--- a/src/gallium/drivers/radeon/r600_pipe_common.c
+++ b/src/gallium/drivers/radeon/r600_pipe_common.c
@@ -136,8 +136,12 @@ static void r600_memory_barrier(struct pipe_context *ctx, unsigned flags)
 void r600_preflush_suspend_features(struct r600_common_context *ctx)
 {
 	/* suspend queries */
-	if (!LIST_IS_EMPTY(&ctx->active_nontimer_queries))
+	if (ctx->num_cs_dw_nontimer_queries_suspend) {
+		/* Since non-timer queries are suspended during blits,
+		 * we have to guard against double-suspends. */
 		r600_suspend_nontimer_queries(ctx);
+		ctx->nontimer_queries_suspended_by_flush = true;
+	}
 	if (!LIST_IS_EMPTY(&ctx->active_timer_queries))
 		r600_suspend_timer_queries(ctx);
 
@@ -158,8 +162,10 @@ void r600_postflush_resume_features(struct r600_common_context *ctx)
 	/* resume queries */
 	if (!LIST_IS_EMPTY(&ctx->active_timer_queries))
 		r600_resume_timer_queries(ctx);
-	if (!LIST_IS_EMPTY(&ctx->active_nontimer_queries))
+	if (ctx->nontimer_queries_suspended_by_flush) {
+		ctx->nontimer_queries_suspended_by_flush = false;
 		r600_resume_nontimer_queries(ctx);
+	}
 }
 
 static void r600_flush_from_st(struct pipe_context *ctx,
diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h b/src/gallium/drivers/radeon/r600_pipe_common.h
index 253d657..a4f3fce 100644
--- a/src/gallium/drivers/radeon/r600_pipe_common.h
+++ b/src/gallium/drivers/radeon/r600_pipe_common.h
@@ -396,6 +396,7 @@ struct r600_common_context {
 	struct list_head		active_nontimer_queries;
 	struct list_head		active_timer_queries;
 	unsigned			num_cs_dw_nontimer_queries_suspend;
+	bool				nontimer_queries_suspended_by_flush;
 	unsigned			num_cs_dw_timer_queries_suspend;
 	/* Additional hardware info. */
 	unsigned			backend_mask;
-- 
2.5.0