dwc2_hsotg_unmap_dma(9)

📦 version 7.3.1, in nixpkgs unstable

💅 dwc2_hsotg_unmap_dma(9) — the Kernel API Manual, bestie edition 🎀

okay so you found yourself in the kernel API manual, section 9, staring at dwc2_hsotg_unmap_dma. Don't panic. This is genuinely just the cleanup step, and honestly? She's iconic for it. Let's get into it ✨

🌸 NAME 🌸

dwc2_hsotg_unmap_dma — unmap the DMA memory being used for the request

like yes that's the whole name, she tells you exactly what she is, we love a transparent queen 🫶

✨ SYNOPSIS ✨

void dwc2_hsotg_unmap_dma (struct dwc2_hsotg *hsotg , struct
dwc2_hsotg_ep *hs_ep , struct dwc2_hsotg_req *hs_req );

note the void — she returns nothing, she does not owe you a status code, she simply does the thing and leaves 💅

🦋 ARGUMENTS 🦋

Three (3) besties walk into a function:

  • hsotg — The device state. this is the big picture, the main character, the whole device's vibe check 🌈
  • hs_ep — The endpoint for the request. okay so this is which endpoint we're talking about, periodt ✨
  • hs_req — The request being processed. the actual request in question, the one getting unmapped 🎀

💖 DESCRIPTION 💖

This is the reverse of dwc2_hsotg_map_dma. literally the undo button, the "jk bestie" of DMA mapping 😭

She's called for the completion of a request, and her whole job is to make sure the buffer is ready for access by the caller. That's it. That's the arc. no cap 💜

think of dwc2_hsotg_map_dma as the "get ready" and this one as the "you're done, come back to the group chat" — they are a matched set and you should never invoke one without the other, iykyk 🧚

🔥 SEE ALSO 🔥

okay this list is long and I need you to know I did not skip a single one, we do not leave people on read in this house 💀 first up, the kernel file where all this lives:

  • Kernel file ./drivers/usb/dwc2/gadget.c

and then, in order, the whole squad:

eighty-two references and a kernel file, and every single one made the cut 🔥 that's the whole friend group, no one got left out of the photo 🌸

and that's the page, bestie 🫶 this one lives in ./drivers/usb/dwc2, and the manual itself is dated October 2026 — so go forth, unmap that DMA, and remember: the buffer's gotta be ready for the caller. slay 💜✨🎀

📦 where this page comes from