dwc2_hcd_qh_init_ddma(9)

💅 dwc2_hcd_qh_init_ddma — a Kernel API Manual moment

okay so bestie, buckle up, because this is a page from the Kernel API Manual and it's literally about waking up a QH structure's Descriptor DMA members. yes, that's a real sentence. yes, it slaps. 🌸

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✨ NAME ✨

dwc2_hcd_qh_init_ddma — Initializes a QH structure's Descriptor DMA related members 🎀

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🦋 SYNOPSIS 🦋

int dwc2_hcd_qh_init_ddma (struct dwc2_hsotg *hsotg , struct dwc2_qh *qh
, gfp_t mem_flags );

that's the whole vibe right there. three params, one int return, no cap. 👑

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🌈 ARGUMENTS 🌈

• hsotg — The HCD state structure for the DWC OTG controller. this is the main character of the whole controller situation, fr fr.
• qh — The QH to init. that's the queue head you're about to breathe life into. 🫶
• mem_flags — Indicates the type of memory allocation. it's giving "please tell me how to allocate my memory" energy. 💫

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😭 RETURN 😭

0 if successful, negative error code otherwise.

so like, 0 = slay, negative = not slay. keep an eye on it. ⭐

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💖 DESCRIPTION 💖

Allocates memory for the descriptor list.

and then — and this is the iconic part — for the first periodic QH, it allocates memory for the FrameList and enables periodic scheduling. highkey a lot of responsibility for one little init function. 🧚

ngl, this is the function that sets things up so everything downstream can actually function. no pressure or anything. 💅

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👑 SEE ALSO 👑

• Kernel file ./drivers/usb/dwc2/hcd_ddma.c — the whole friend group lives here 🍓
• dwc2_hcd_qh_free_ddma(9) — the clean-up bestie
• dwc2_hcd_start_xfer_ddma(9) — the "let's gooo" bestie
• dwc2_hcd_complete_xfer_ddma(9) — the "we did it" bestie

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and that's the page!! 🌸 source & version vibes: ./drivers/usb/dwc2, dated October 2026, and the manual name is dwc2_hcd_qh_init_ddma(9) in case you forgot. mwah. 💜✨