sdw_acquire_bus_lock(9)

💅 sdw_acquire_bus_lock(9) — like, the Kernel API Manual page you actually wanna read 🎀

okay so bestie, welcome to the Kernel API Manual entry for sdw_acquire_bus_lock(9) — she's short, she's sweet, and she holds a lock. main character energy fr fr. 💖

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✨ NAME ✨

sdw_acquire_bus_lock — grabs the bus lock for, like, all the Master runtime(s). every single one. no cap. 🔥

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🦋 SYNOPSIS 🦋

void sdw_acquire_bus_lock (struct sdw_stream_runtime *stream );

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🌸 ARGUMENTS 🌸

• stream — the SoundWire stream in question 🫶. yeah. that's the whole argument list. she's lowkey uncomplicated.

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👑 DESCRIPTION 👑

So what she does is: acquire bus_lock for each and every one of the master runtime (m_rt) parts of this stream 💅 — because you gotta reconfigure the bus, and you can't just do that unsupervised. think of it as herding all the master runtimes into one room and locking the door so nobody messes with the bus mid-reconfigure. iconic behavior, honestly. ✨

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💀 NOTE 💀

okay this part matters, so listen: this function gets called from SoundWire stream ops, and it is expected that a global lock is held before acquiring bus_lock. so like… the lock's already locked, bestie. don't come in here trying to acquire things with no global lock held. that's the vibe check and you will fail it. 😭 🔒

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🌈 SEE ALSO 🌈

Kernel file ./drivers/soundwire/stream.c, plus the whole friend group:

• sdw_program_port_params(9)
• sdw_enable_disable_slave_ports(9)
• sdw_enable_disable_ports(9)
• sdw_prep_deprep_ports(9)
• sdw_notify_config(9)
• sdw_program_params(9)
• sdw_ml_sync_bank_switch(9)
• sdw_slave_rt_alloc(9)
• sdw_slave_rt_config(9)
• sdw_slave_rt_free(9)
• sdw_master_rt_alloc(9)
• sdw_master_rt_config(9)
• sdw_master_rt_free(9)
• sdw_config_stream(9)
• sdw_get_slave_dpn_prop(9)
• sdw_release_bus_lock(9)
• sdw_prepare_stream(9)
• sdw_enable_stream(9)
• sdw_disable_stream(9)
• sdw_deprepare_stream(9)
• sdw_alloc_stream(9)
• sdw_startup_stream(9)
• sdw_shutdown_stream(9)
• sdw_release_stream(9)
• sdw_stream_add_master(9)
• sdw_stream_remove_master(9)
• sdw_stream_add_slave(9)
• sdw_stream_remove_slave(9)

like. the whole squad. go read them too, iykyk 🧚‍♀️

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and that's the page, bestie!! 🍓 it lives in ./drivers/soundwire and this particular drop is dated October 2026 — see you in the next release, mwah 💜 🎀🦋🌟