snd_power_ref_and_wait(9)

💖 snd_power_ref_and_wait(9) 💖

okay so bestie, welcome to the Kernel API Manual — we're talking about snd_power_ref_and_wait(9) today and honestly? it's giving "hold my hand until the soundcard wakes up" energy 🫶

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✨ NAME ✨

snd_power_ref_and_wait — the function that literally sits there and waits until the card gets powered up 🔥

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🌸 SYNOPSIS 🌸

int snd_power_ref_and_wait (struct snd_card *card );

like, that's the whole vibe. one card, one return value, no drama 💅

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🎀 ARGUMENTS 🎀

• card — the soundcard structure, aka the main character of this whole situation 👑

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🦋 DESCRIPTION 🦋

so what it does: it takes the power_ref reference count of the given card, and then it waits until that card gets powered up to the SNDRV_CTL_POWER_D0 state. iconic behavior, no cap ⭐

and here's the cute part — the refcount gets pulled down again while it's sleeping, all the way until power-up happens. which means this function is genuinely useful for syncing the floating control ops accesses, typically around calling control ops. iykyk 😌

⚠️ heads up bestie: the caller needs to pull down the refcount via snd_power_unref later, when this function returns 0. don't forget, fr fr — that's your responsibility, not the function's 🙈

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💀 RETURN 💀

Zero if successful, or a negative error code. that's it, that's the whole treasure map 🗺️✨

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🌈 SEE ALSO 🌈

Kernel file ./sound/core/init.c — plus this whole friend group right here:

• snd_device_alloc(9)
• snd_card_new(9)
• snd_devm_card_new(9)
• snd_card_free_on_error(9)
• snd_card_ref(9)
• snd_card_disconnect(9)
• snd_card_disconnect_sync(9)
• snd_card_free_when_closed(9)
• snd_card_free(9)
• snd_card_set_id(9)
• snd_card_add_dev_attr(9)
• snd_card_register(9)
• snd_component_add(9)
• snd_card_file_add(9)
• snd_card_file_remove(9)
• snd_power_wait(9)

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and that's the page!! sourced straight from ./sound/core, dated October 2026 — mwah, go forth and sync those control ops 💜🎀🧚