From a5b7365f28c191df6b93f60942d2b9a9fe71746c Mon Sep 17 00:00:00 2001 From: Pierre-Louis Bossart Date: Mon, 3 Jun 2024 14:58:41 +0800 Subject: [PATCH] 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: Pierre-Louis Bossart Reviewed-by: Rander Wang Signed-off-by: Bard Liao Link: https://lore.kernel.org/r/20240603065841.4860-2-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul --- drivers/soundwire/stream.c | 5 +++++ include/linux/soundwire/sdw.h | 2 ++ 2 files changed, 7 insertions(+) diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c index 4e9e7d2a942d..7aa4900dcf31 100644 --- a/drivers/soundwire/stream.c +++ b/drivers/soundwire/stream.c @@ -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--; } /** diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index 13e96d8b7423..94fc1b57c57b 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -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,