[Mesa-dev] [PATCH] radeonsi: fix query buffer allocation

[Timothy Arceri]

Fix the logic for buffer full check on alloc.

This patch just takes the fix Nicolai attached to the bug report
and updates it to work on master.

Fixes: e0f0d3675d4 ("radeonsi: factor si_query_buffer logic out of si_query_hw")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109561
---
 src/gallium/drivers/radeonsi/si_query.c | 42 +++++++++++++------------
 src/gallium/drivers/radeonsi/si_query.h |  5 +--
 2 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_query.c b/src/gallium/drivers/radeonsi/si_query.c
index 266b9d3ce84..04685b8bb3f 100644
--- a/src/gallium/drivers/radeonsi/si_query.c
+++ b/src/gallium/drivers/radeonsi/si_query.c
@@ -561,29 +561,31 @@ bool si_query_buffer_alloc(struct si_context *sctx, struct si_query_buffer *buff
 			   bool (*prepare_buffer)(struct si_context *, struct si_query_buffer*),
 			   unsigned size)
 {
-	if (buffer->buf && buffer->results_end + size >= buffer->buf->b.b.width0)
-		return true;
+	bool unprepared = buffer->unprepared;
+	buffer->unprepared = false;
+
+	if (!buffer->buf || buffer->results_end + size > buffer->buf->b.b.width0) {
+		if (buffer->buf) {
+			struct si_query_buffer *qbuf = MALLOC_STRUCT(si_query_buffer);
+			memcpy(qbuf, buffer, sizeof(*qbuf));
+			buffer->previous = qbuf;
+		}
+		buffer->results_end = 0;
 
-	if (buffer->buf) {
-		struct si_query_buffer *qbuf = MALLOC_STRUCT(si_query_buffer);
-		memcpy(qbuf, buffer, sizeof(*qbuf));
-		buffer->previous = qbuf;
+		/* Queries are normally read by the CPU after
+		 * being written by the gpu, hence staging is probably a good
+		 * usage pattern.
+		 */
+		struct si_screen *screen = sctx->screen;
+		unsigned buf_size = MAX2(size, screen->info.min_alloc_size);
+		buffer->buf = si_resource(
+			pipe_buffer_create(&screen->b, 0, PIPE_USAGE_STAGING, buf_size));
+		if (unlikely(!buffer->buf))
+			return false;
+		unprepared = true;
 	}
 
-	buffer->results_end = 0;
-
-	/* Queries are normally read by the CPU after
-	 * being written by the gpu, hence staging is probably a good
-	 * usage pattern.
-	 */
-	struct si_screen *screen = sctx->screen;
-	unsigned buf_size = MAX2(size, screen->info.min_alloc_size);
-	buffer->buf = si_resource(
-		pipe_buffer_create(&screen->b, 0, PIPE_USAGE_STAGING, buf_size));
-	if (unlikely(!buffer->buf))
-		return false;
-
-	if (prepare_buffer) {
+	if (unprepared && prepare_buffer) {
 		if (unlikely(!prepare_buffer(sctx, buffer))) {
 			si_resource_reference(&buffer->buf, NULL);
 			return false;
diff --git a/src/gallium/drivers/radeonsi/si_query.h b/src/gallium/drivers/radeonsi/si_query.h
index aaf0bd03aca..c61af51d57c 100644
--- a/src/gallium/drivers/radeonsi/si_query.h
+++ b/src/gallium/drivers/radeonsi/si_query.h
@@ -177,12 +177,13 @@ struct si_query_hw_ops {
 struct si_query_buffer {
 	/* The buffer where query results are stored. */
 	struct si_resource		*buf;
-	/* Offset of the next free result after current query data */
-	unsigned			results_end;
 	/* If a query buffer is full, a new buffer is created and the old one
 	 * is put in here. When we calculate the result, we sum up the samples
 	 * from all buffers. */
 	struct si_query_buffer	*previous;
+	/* Offset of the next free result after current query data */
+	unsigned			results_end;
+	bool unprepared;
 };
 
 void si_query_buffer_destroy(struct si_screen *sctx, struct si_query_buffer *buffer);
-- 
2.20.1