snd_hdac_stream_assign(9)

📦 version 7.3.1, in nixpkgs unstable

✨ snd_hdac_stream_assign(9) ✨

okay so bestie, welcome to the Kernel API Manual 💖 this one's about snd_hdac_stream_assign, living in that ./sound/hda/core neck of the woods, and honestly it's giving "matchmaker for PCM streams" energy 🫶

🌸 NAME 🌸

snd_hdac_stream_assign — assign a stream for the PCM 💅

🎀 SYNOPSIS 🎀

struct hdac_stream * snd_hdac_stream_assign (struct hdac_bus *bus ,
struct snd_pcm_substream *substream );

like, that's the whole signature, no notes ✨

🦋 ARGUMENTS 🦋

  • bus — the HD-audio core bus, your main character 🌈
  • substream — the PCM substream we're trying to assign, the one that needs a stream bestie 💜

🔥 DESCRIPTION 🔥

So here's the vibe: it goes looking for an unused stream for the given PCM substream, assigns it, and hands you back the stream object. Iconic. 🎀

If no stream is free? It returns NULL. 😭 no cap, that's just how it is.

The function tries to keep using the same stream object when it's been used beforehand — lowkey loyal like that 🫶

Also, when the bus->reverse_assign flag is set, the last free or matching entry is returned. And why?? Because some strange codecs need it, bestie 💀 that's literally the reason, "some strange codecs."

fr fr, that reverse_assign detail is not a typo — last free or matching entry, not the first. iykyk 🧚

👑 SEE ALSO 👑

Kernel file ./sound/hda/core/stream.c plus the whole squad:

and that's the whole page, bestie 🍓 this little gem comes from ./sound/hda/core and it's dated October 2026 — slay, go assign some streams, periodt 💅✨

📦 where this page comes from