pcm_trigger(9)

🎧 pcm_trigger(9) — a Kernel API Manual moment 👑

🌸 NAME 🌸

pcm_trigger — implements the trigger callback function for the PCM middle layer. bestie, that’s literally the whole gig 💅

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✨ SYNOPSIS ✨

int pcm_trigger (struct snd_pcm_substream *substream , int cmd );

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🎀 ARGUMENTS 🎀

• substream — the substream pointer. yes, it’s giving “pointer to the substream” energy 🫶
• cmd — the action to perform. this is where the trigger tea gets specified 👀

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💅 DESCRIPTION 💅

Okay so this function gets called when the PCM is started, stopped, or paused. The action is specified in the second argument, SNDRV_PCM_TRIGGER_XXX — iconic behavior, no cap ✨

Return vibe check: 0 on success, or an error code otherwise. periodt. 😌

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🦋 SEE ALSO 🦋

If you’re going deeper, the Kernel file is ./drivers/most/most_snd.c. Also these kernel besties are right here:

• struct channel(9)
• get_channel(9)
• copy_data(9)
• playback_thread(9)
• pcm_open(9)
• pcm_close(9)
• pcm_prepare(9)
• pcm_pointer(9)
• audio_probe_channel(9)
• audio_disconnect_channel(9)
• audio_rx_completion(9)
• audio_tx_completion(9)

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mwah 💋 this little page comes from ./drivers/most, dated October 2026 — catch you in the kernel, bestie 🫶