dspio_scp(9)

📦 version 7.3.1, in nixpkgs unstable

💅 dspio_scp — a Kernel API Manual moment (yes, the (9) girlies, this one's for you)

okay so bestie, we're deep in the kernel sound stack and it's giving "who let the DSP cook" 😭 this page is literally dspio_scp from the Kernel API Manual, and she's here to Prepare and send the SCP message to DSP. no cap, that's the whole name. let's get into it 🎀

✨ NAME ✨

dspio_scp — prepare and send the SCP message to DSP 💌

the name is right there in the function, bestie, we love a self-explanatory icon 👑

🌸 SYNOPSIS 🌸

like, here's the whole signature, copy-paste it into your soul:

int dspio_scp (struct hda_codec *codec , int mod_id , int src_id , int
req , int dir , const void *data , unsigned int len , void *reply ,
unsigned int *reply_len );

it returns an int, it takes a lot of arguments, and honestly? she's thriving. 🦋

🫶 ARGUMENTS 🫶

every single one, we don't skip, we don't gatekeep:

  • codec — the HDA codec. your main character, fr. 🔥
  • mod_id — ID of the DSP module to send the command. which module are we bothering today, bestie?
  • src_id — ID of the source. like, where's it coming from?
  • req — ID of request to send to the DSP module. the actual ask. 💅
  • dir — SET or GET. are we giving or are we receiving? that's the vibe check. ⭐
  • data — pointer to the data to send with the request, request specific. yes it's vague, no I can't fix that, that's just how she is 🙈
  • len — length of the data, in bytes. count 'em. 💀
  • reply — point to the buffer to hold data returned for a reply. (their wording, not mine — they mean pointer, but we move 🧚)
  • reply_len — length of the reply buffer returned from GET. only the GET girlies get this one 🍓

👑 DESCRIPTION 👑

so what does she do? she prepares and sends that SCP message to the DSP, and then:

Returns zero or a negative error code.

that's it. that's the whole description. zero means slay, negative means something went sideways 😭 check your return value, babe, always. no guessing, no cope, just 0 or a negative error code. periodt. 💜

🌈 SEE ALSO 🌈

go read these next, iykyk:

they're all part of the same little friend group, and honestly they ate 🫶✨

and that's the page!! huge shoutout to the source, ./sound/hda/codecs, dated October 2026, which is also where the dspio_scp(9) header lives — mwah, love you, mean it 💖🎀🦋

📦 where this page comes from