dwc2_hcd_qh_create(9)

💫 dwc2_hcd_qh_create(9) — like, the Kernel API Manual, but make it make sense 💫

okay bestie, gather round, because we're diving into dwc2_hcd_qh_create(9) from the Kernel API Manual and honestly? it's giving "small function, big responsibility" energy. 👑

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✨ NAME ✨

dwc2_hcd_qh_create — allocates and initializes a QH. that's it, that's the whole vibe. it makes the QH and gets it ready to go. 🎀

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🌸 SYNOPSIS 🌸

struct dwc2_qh * dwc2_hcd_qh_create (struct dwc2_hsotg *hsotg , struct
dwc2_hcd_urb *urb , gfp_t mem_flags );

look at her. three args, returns a pointer, absolutely slaying. 💅

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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. 👑
• urb — holds the info about the device/endpoint that's needed to initialize the QH. basically the little info packet that tells the QH what it's gonna be when it grows up. 🐛→🦋
• mem_flags — flags for allocating memory. yes, the gfp_t situation. it's how you tell the allocator what mood it should be in. ✨

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💖 RETURN 💖

pointer to the newly allocated QH, or NULL on error. so like… check it, bestie. if it's NULL, something went sideways and you should not be dereferencing that. 😭

ngl, NULL on error is the classic "it's not you, it's the allocation" moment. handle it. 🙈

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🌈 SEE ALSO 🌈

the whole squad, no cap. and also the kernel file ./drivers/usb/dwc2/hcd_queue.c — that's where the lore lives. 📖

• dwc2_periodic_channel_available(9)
• dwc2_check_periodic_bandwidth(9)
• pmap_schedule(9)
• pmap_unschedule(9)
• dwc2_get_ls_map(9)
• dwc2_qh_print(9)
• dwc2_qh_schedule_print(9)
• dwc2_ls_pmap_schedule(9)
• dwc2_ls_pmap_unschedule(9)
• dwc2_hs_pmap_schedule(9)
• dwc2_hs_pmap_unschedule(9)
• dwc2_uframe_schedule_split(9)
• dwc2_uframe_schedule_hs(9)
• dwc2_uframe_schedule_ls(9)
• dwc2_uframe_schedule(9)
• dwc2_uframe_unschedule(9)
• dwc2_pick_first_frame(9)
• dwc2_do_reserve(9)
• dwc2_do_unreserve(9)
• dwc2_unreserve_timer_fn(9)
• dwc2_check_max_xfer_size(9)
• dwc2_schedule_periodic(9)
• dwc2_deschedule_periodic(9)
• dwc2_wait_timer_fn(9)
• dwc2_qh_init(9)
• dwc2_hcd_qh_free(9)
• dwc2_hcd_qh_add(9)
• dwc2_hcd_qh_unlink(9)
• dwc2_next_for_periodic_split(9)
• dwc2_next_periodic_start(9)
• dwc2_hcd_qtd_init(9)
• dwc2_hcd_qtd_add(9)

like I said. the whole squad. 🫶

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and that's the page, bestie ✨ — brought to you by ./drivers/usb/dwc2, vintage October 2026, page dwc2_hcd_qh_create(9). go forth and allocate responsibly 💜🎀