acpi_dma_update_dma_spec(9)

📦 version 7.3.1, in nixpkgs unstable

💅 acpi_dma_update_dma_spec(9)

ok so this is a page from the Kernel API Manual, and bestie, it's a little function with one very specific job. let's get into it 🫶

✨ NAME ✨

acpi_dma_update_dma_spec — get your dma specifier all prepped and cute so it can be handed off to the translation function 💖

🌸 SYNOPSIS 🌸

int acpi_dma_update_dma_spec (struct acpi_dma *adma , struct
       acpi_dma_spec *dma_spec );

literally two args, one int coming back at you. slay.

🎀 ARGUMENTS 🎀

  • adma — the struct acpi_dma of the DMA controller. like, the controller in question, bestie 🦋
  • dma_spec — the dma specifier that's about to get updated ✨

💜 DESCRIPTION 💜

ok so per the ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource Descriptor", the DMA Request Line bits are a platform-relative number that uniquely identifies the request line that got assigned. iykyk 👑

and the request line-to-Controller mapping? that whole situation is handled in a controller-specific OS driver. so basically, because that mapping lives over there, we can safely adjust slave_id once the appropriate controller has been found. no cap, that's the whole reason this is safe 🙈

🔥 RETURN 🔥

  • 0 — if no information is available
  • -1 — on mismatch 💀
  • 1 — otherwise ✨

👑 SEE ALSO 👑

Kernel file ./drivers/dma/acpi-dma.c — go look, it's right there 🍓

and that's the whole page, bestie 💅 this one lives in ./drivers/dma and it's stamped October 2026 — so like, go forth and translate those dma specifiers, mwah 🧚💖

📦 where this page comes from