more patch

src/gallium/drivers/panfrost/pan_context.c

@@ -868,6 +868,58 @@ panfrost_create_fence_fd(struct pipe_context *pctx,
    *pfence = panfrost_fence_from_fd(pan_context(pctx), fd, type);
 }
 
+struct sync_merge_data {
+	char	name[32];
+	int32_t	fd2;
+	int32_t	fence;
+	uint32_t	flags;
+	uint32_t	pad;
+};
+
+#define SYNC_IOC_MAGIC		'>'
+#define SYNC_IOC_MERGE		_IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data)
+
+static inline int sync_merge(const char *name, int fd1, int fd2)
+{
+	struct sync_merge_data data = {{0}};
+	int ret;
+
+	data.fd2 = fd2;
+	strncpy(data.name, name, sizeof(data.name));
+
+	do {
+		ret = ioctl(fd1, SYNC_IOC_MERGE, &data);
+	} while (ret == -1 && (errno == EINTR || errno == EAGAIN));
+
+	if (ret < 0)
+		return ret;
+
+	return data.fence;
+}
+
+static inline int sync_accumulate(const char *name, int *fd1, int fd2)
+{
+	int ret;
+
+	assert(fd2 >= 0);
+
+	if (*fd1 < 0) {
+		*fd1 = dup(fd2);
+		return 0;
+	}
+
+	ret = sync_merge(name, *fd1, fd2);
+	if (ret < 0) {
+		/* leave *fd1 as it is */
+		return ret;
+	}
+
+	close(*fd1);
+	*fd1 = ret;
+
+	return 0;
+}
+
 static void
 panfrost_fence_server_sync(struct pipe_context *pctx,
                            struct pipe_fence_handle *f)