snd_pcm_set_...d_buffer_all(9)

📦 version 7.3.1, in nixpkgs unstable

💅 snd_pcm_set_...d_buffer_all(9) 💅

okay so this is a page straight out of the Kernel API Manual, bestie — yes, the Kernel API Manual, we're in the big leagues now 🎀 — and the function's full government name is snd_pcm_set_managed_buffer_all, it's just the header that had to abbreviate it. iykyk.

✨ NAME ✨

snd_pcm_set_managed_buffer_all — set up buffer management for all substreams for all substreams

no fr, it says "for all substreams" twice and honestly? she's not wrong, she's just thorough 💅

🦋 SYNOPSIS 🦋

int snd_pcm_set_managed_buffer_all (struct snd_pcm *pcm , int type ,
       struct device *data , size_t size , size_t max );

🌸 ARGUMENTS 🌸

  • pcm — the pcm instance. the main character, the one we're doing all this for 👑
  • type — DMA type, and it's one of the SNDRV_DMA_TYPE_* girlies ✨
  • data — DMA type dependent data. so like, the data depends on whatever type you picked, bestie 🌈
  • size — the requested pre-allocation size in bytes. literally the number of bytes you're asking for upfront 💖
  • max — the max. allowed pre-allocation size. the ceiling, the limit, the "don't get too comfortable" 🫶

💜 DESCRIPTION 💜

so what does she actually do? she does pre-allocation to all substreams of the given pcm, for the specified DMA type and size 🔥 and then — the important part — she sets the managed_buffer_alloc flag to each substream. every single one. no substream left behind, periodt 🌟

⭐ RETURN ⭐

  • zero if successful 🎉
  • or a negative error code 😭 (not me getting a negative error code)

🧚 SEE ALSO 🧚

the kernel file ./sound/core/pcm_memory.c is where the magic lives, plus her whole friendship circle:

and that's the whole page, bestie 💅✨ go off and pre-allocate responsibly — this one's from ./sound/core, dated October 2026, all wrapped up in the Kernel API Manual 🎀🦋💖

📦 where this page comes from