From d3bd687bc2c4bd05a374f014a95570b293a87417 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Thu, 30 Mar 2023 14:53:44 +0200
Subject: [PATCH] buffers: add new ASYNC flag

Make sure we allocate at least 2 buffers when we are dealing with an
ASYNC node. This ensures that an adapter without a converter will at
least negotiate to 2 buffers when the follower stream is async (such as
is the case with pw-cat).
---
 src/pipewire/buffers.c   | 4 ++++
 src/pipewire/buffers.h   | 1 +
 src/pipewire/impl-port.c | 7 +++++--
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/pipewire/buffers.c b/src/pipewire/buffers.c
index 8c9d9dd58..75896b691 100644
--- a/src/pipewire/buffers.c
+++ b/src/pipewire/buffers.c
@@ -292,6 +292,9 @@ int pw_buffers_negotiate(struct pw_context *context, uint32_t flags,
 		align = SPA_MAX(align, qalign);
 		types = qtypes;
 
+		if (SPA_FLAG_IS_SET(flags, PW_BUFFERS_FLAG_ASYNC))
+			max_buffers = SPA_MAX(2u, max_buffers);
+
 		pw_log_debug("%p: %d %d %d %d %d %d -> %d %zd %zd %d %zd %d", result,
 				qblocks, qminsize, qstride, qmax_buffers, qalign, qtypes,
 				blocks, minsize, stride, max_buffers, align, types);
@@ -300,6 +303,7 @@ int pw_buffers_negotiate(struct pw_context *context, uint32_t flags,
 		minsize = 8192;
 		max_buffers = 2;
 	}
+
 	if (SPA_FLAG_IS_SET(flags, PW_BUFFERS_FLAG_SHARED_MEM)) {
 		if (types != SPA_ID_INVALID)
 			SPA_FLAG_CLEAR(types, 1<<SPA_DATA_MemPtr);
diff --git a/src/pipewire/buffers.h b/src/pipewire/buffers.h
index 5d034bd13..9c1ae2b78 100644
--- a/src/pipewire/buffers.h
+++ b/src/pipewire/buffers.h
@@ -29,6 +29,7 @@ extern "C" {
 #define PW_BUFFERS_FLAG_DYNAMIC		(1<<2)	/**< buffers have dynamic data */
 #define PW_BUFFERS_FLAG_SHARED_MEM	(1<<3)	/**< buffers need shared memory */
 #define PW_BUFFERS_FLAG_IN_PRIORITY	(1<<4)	/**< input parameters have priority */
+#define PW_BUFFERS_FLAG_ASYNC		(1<<5)	/**< one of the nodes is async */
 
 struct pw_buffers {
 	struct pw_memblock *mem;	/**< allocated buffer memory */
diff --git a/src/pipewire/impl-port.c b/src/pipewire/impl-port.c
index 60b1ba512..b12223afa 100644
--- a/src/pipewire/impl-port.c
+++ b/src/pipewire/impl-port.c
@@ -1574,9 +1574,12 @@ static int negotiate_mixer_buffers(struct pw_impl_port *port, uint32_t flags,
 
 		/* try dynamic data */
 		alloc_flags = PW_BUFFERS_FLAG_DYNAMIC;
+		if (SPA_FLAG_IS_SET(node->spa_flags, SPA_NODE_FLAG_ASYNC))
+			alloc_flags |= PW_BUFFERS_FLAG_ASYNC;
 
-		pw_log_debug("%p: %d.%d negotiate %d buffers on node: %p",
-				port, port->direction, port->port_id, n_buffers, node->node);
+		pw_log_debug("%p: %d.%d negotiate %d buffers on node: %p flags:%08x",
+				port, port->direction, port->port_id, n_buffers, node->node,
+				alloc_flags);
 
 		if (port->added) {
 			pw_loop_invoke(node->data_loop, do_remove_port, SPA_ID_INVALID, NULL, 0, true, port);