cs_dsp_coeff_write_ctrl(9)

📦 version 7.3.1, in nixpkgs unstable

💅 cs_dsp_coeff_write_ctrl 💅

okay bestie, so this is a page from the Kernel API Manual and it's literally all about cs_dsp_coeff_write_ctrl — the little function that shoves your buffer into a coefficient control. it's giving "small but important" energy, yk? 🎀

✨ NAME ✨

cs_dsp_coeff_write_ctrl — writes the given buffer to the given coefficient control 🦋

no cap, that's the whole vibe. it takes a buffer and it writes it into the coefficient control you point it at.

🌸 SYNOPSIS 🌸

int cs_dsp_coeff_write_ctrl (struct cs_dsp_coeff_ctl *ctl , unsigned int
off , const void *buf , size_t len );

bestie look at it. returns an int, takes four things. iconic signature tbh 🔥

💖 ARGUMENTS 💖

  • ctl — pointer to coefficient control. this is your main character — the coefficient control you're writing into, periodt 💅
  • off — word offset at which data should be written. lowkey important: it's a word offset, not a byte offset, iykyk ✨
  • buf — the buffer to write to the given control. this is the actual data payload, the little gift you're dropping off 🎁
  • len — the length of the buffer in bytes. note bestie: the length is in bytes even though off is in words — do not mix those up fr fr 😭

🦋 DESCRIPTION 🦋

so here's the tea ☕ — you must call this with pwr_lock held. not optional, not a suggestion, it's a whole requirement. hold the lock or don't come to the function 🙈

🫶 RETURN 🫶

it returns an int and the values mean things, so pay attention bestie:

  • < 0 on error 💀
  • 1 when the control value changed 🌈
  • 0 when it has not ⭐

so like, 1 and 0 are both "fine" outcomes, they just tell you whether anything actually moved. < 0 is the "something went wrong" vibe.

👑 SEE ALSO 👑

the kernel file this lives in, for the curious girlies:

./drivers/firmware/cirrus/cs_dsp.c

and now the full friend group — every single one, no skipping, because everyone deserves their moment ✨:

and that's the whole page bestie, you ate that 🍓

stay safe out there and remember: hold pwr_lock. i don't make the rules, the kernel does 💀

✿ sourced from ./drivers/firmware/cirrus, dated October 2026, and yes it's cs_dsp_coeff_write_ctrl(9) — mwah 💋 ✿

📦 where this page comes from