hw_ep_prime(9)

💅 hw_ep_prime (section 9, Kernel API Manual, bestie)

okay so picture this: we're deep in the kernel API manual, section 9, and the star of the show is hw_ep_prime — the function whose whole entire job is priming an endpoint, and like... executing it without interruption. no pauses. no "brb". it's giving main character energy 🔥

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✨ NAME ✨

hw_ep_prime — primes the endpoint, and does it with zero interruption. periodt. 💅

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🦋 SYNOPSIS 🦋

int hw_ep_prime (struct ci_hdrc *ci , int num , int dir , int is_ctrl );

like literally that's the whole signature, copy it exactly, don't @ me 🫶

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🎀 ARGUMENTS 🎀

• ci — the controller. yes, the controller. the whole vibe. 👑
• num — the endpoint number.
• dir — the endpoint direction (which way it's going, iykyk).
• is_ctrl — true if this is a control endpoint. true/false moment fr fr.

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🌸 DESCRIPTION 🌸

so what does it do? this function returns an error code. that's it. that's the description. ngl it's lowkey mysterious but we respect it 💀✨

no cap, the original really is that short — the docs say it returns an error code and then simply move on. iconic behaviour honestly.

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🌈 SEE ALSO 🌈

bestie there is a whole friend group here, all hanging out in the kernel file ./drivers/usb/chipidea/udc.c — go say hi to every single one, no skipping, we don't do that here 🫶:

• hw_ep_bit(9)
• hw_device_state(9)
• hw_ep_flush(9)
• hw_ep_disable(9)
• hw_ep_enable(9)
• hw_ep_get_halt(9)
• hw_ep_set_halt(9)
• hw_port_is_high_speed(9)
• hw_test_and_clear_complete(9)
• hw_test_and_clear_intr_active(9)
• hw_test_and_clear_setup_guard(9)
• hw_test_and_set_setup_guard(9)
• hw_usb_set_address(9)
• hw_usb_reset(9)
• _usb_addr(9)
• _hardware_enqueue(9)
• free_pending_td(9)
• _hardware_dequeue(9)
• _ep_nuke(9)
• _gadget_stop_activity(9)
• isr_reset_handler(9)
• isr_get_status_complete(9)
• _ep_queue(9)
• isr_get_status_response(9)
• isr_setup_status_complete(9)
• isr_setup_status_phase(9)
• isr_tr_complete_low(9)
• isr_setup_packet_handler(9)
• isr_tr_complete_handler(9)
• ci_udc_start(9)
• udc_start(9)
• udc_stop(9)
• ci_hdrc_gadget_init(9)

that's the roster. every name. all of them. slay. 🧚

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and that's a wrap on hw_ep_prime(9) from the ./drivers/usb/chipidea directory, dated October 2026 — mwah, thanks for reading bestie, go touch some registers 💖