Commit a5b7365f authored by Pierre-Louis Bossart's avatar Pierre-Louis Bossart Committed by Vinod Koul
Browse files

soundwire: bus: add stream refcount 



The notion of stream is by construction based on a multi-bus
capability, to allow for aggregation of Peripheral devices or
functions located on different segments. We currently count how many
master_rt contexts are used by a stream, but we don't have the dual
refcount of how many streams are allocated on a given bus. This
refcount will be useful to check if BTP/BRA streams can be allocated.

Note that the stream_refcount is modified in sdw_master_rt_alloc() and
sdw_master_rt_free() which are both called with the bus_lock mutex
held, so there's no need for refcount_ primitives for additional
protection.

Signed-off-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: default avatarRander Wang <rander.wang@intel.com>
Signed-off-by: default avatarBard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20240603065841.4860-2-yung-chuan.liao@linux.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent fe46d2a4

drivers/soundwire/stream.c

+5 −0
Original line number Diff line number Diff line
@@ -1181,6 +1181,8 @@ static struct sdw_master_runtime 
	m_rt->bus = bus;

	m_rt->stream = stream;



	bus->stream_refcount++;



	return m_rt;

}
@@ -1217,6 +1219,7 @@ static void sdw_master_rt_free(struct sdw_master_runtime *m_rt, 
			       struct sdw_stream_runtime *stream)

{

	struct sdw_slave_runtime *s_rt, *_s_rt;

	struct sdw_bus *bus = m_rt->bus;



	list_for_each_entry_safe(s_rt, _s_rt, &m_rt->slave_rt_list, m_rt_node) {

		sdw_slave_port_free(s_rt->slave, stream);
@@ -1226,6 +1229,8 @@ static void sdw_master_rt_free(struct sdw_master_runtime *m_rt, 
	list_del(&m_rt->stream_node);

	list_del(&m_rt->bus_node);

	kfree(m_rt);



	bus->stream_refcount--;

}



/**

include/linux/soundwire/sdw.h

+2 −0
Original line number Diff line number Diff line
@@ -903,6 +903,7 @@ struct sdw_master_ops { 
 * meaningful if multi_link is set. If set to 1, hardware-based

 * synchronization will be used even if a stream only uses a single

 * SoundWire segment.

 * @stream_refcount: number of streams currently using this bus

 */

struct sdw_bus {

	struct device *dev;
@@ -933,6 +934,7 @@ struct sdw_bus { 
	u32 bank_switch_timeout;

	bool multi_link;

	int hw_sync_min_links;

	int stream_refcount;

};



int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,