ep_write_UDCCSR(9)

💅 ep_write_UDCCSR (9) — the Kernel API Manual glow-up

okay bestie, so we're in the Kernel API Manual today and this page is genuinely short but like… very real. let's get into it ✨

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🌸 NAME 🌸

ep_write_UDCCSR — sets bits in UDCCSR. that's it. that's the whole job. iconic honestly 🎀

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🦋 SYNOPSIS 🦋

void ep_write_UDCCSR (struct pxa_ep *ep , int mask );

like, the way this returns void? no notes. she does her thing and leaves 💅

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💖 ARGUMENTS 💖

• ep — the udc endpoint. that's your little endpoint bestie 🫶
• mask — the bits to set in UDCCR. you hand her the mask, she sets the bits. no cap.

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✨ DESCRIPTION ✨

so what she does is, she sets bits in UDCCSR — and just to be super clear, that's UDCCSR0 and UDCCSR*. yes, both. she's thorough like that. ⭐

and then there's a specific case that gets applied to ep0 👀 — the ACM bit is always set to 1, for SET_INTERFACE and SET_CONFIGURATION. always. every time. it's giving main character energy for real 🔥

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🧚 SEE ALSO 🧚

okay this part is literally a whole group chat, buckle up bestie 💜 — everything lives in the kernel file ./drivers/usb/gadget/udc/pxa27x_udc.c and here's the entire squad:

is_match_usb_pxa(9), find_pxa_ep(9), update_pxa_ep_matches(9), pio_irq_enable(9), pio_irq_disable(9), udc_set_mask_UDCCR(9), udc_clear_mask_UDCCR(9), ep_count_bytes_remain(9), ep_is_empty(9), ep_is_full(9), epout_has_pkt(9), set_ep0state(9), ep0_idle(9), inc_ep_stats_reqs(9), inc_ep_stats_bytes(9), pxa_ep_setup(9), pxa_eps_setup(9), pxa_ep_alloc_request(9), pxa_ep_free_request(9), ep_add_request(9), ep_del_request(9), req_done(9), ep_end_out_req(9), ep0_end_out_req(9), ep_end_in_req(9), ep0_end_in_req(9), nuke(9), read_packet(9), write_packet(9), read_fifo(9), write_fifo(9), read_ep0_fifo(9), write_ep0_fifo(9), pxa_ep_queue(9), pxa_ep_dequeue(9), pxa_ep_set_halt(9), pxa_ep_fifo_status(9), pxa_ep_fifo_flush(9), pxa_ep_enable(9), pxa_ep_disable(9), dplus_pullup(9), pxa_udc_get_frame(9), pxa_udc_wakeup(9), should_enable_udc(9), should_disable_udc(9), pxa_udc_pullup(9), pxa_udc_vbus_session(9), pxa_udc_vbus_draw(9), pxa_udc_phy_event(9), udc_disable(9), udc_init_data(9), udc_enable(9), pxa27x_udc_start(9), stop_activity(9), pxa27x_udc_stop(9), handle_ep0_ctrl_req(9), handle_ep0(9), handle_ep(9), pxa27x_change_configuration(9), pxa27x_change_interface(9), irq_udc_suspend(9), irq_udc_resume(9), irq_udc_reconfig(9), irq_udc_reset(9), pxa_udc_irq(9), pxa_udc_probe(9), pxa_udc_remove(9), pxa_udc_suspend(9), pxa_udc_resume(9)

like… that's everybody. ate and left no crumbs 👑

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🫶 that's the whole page bestie, she's short but she's perfect. now go set some bits, you got this 💖

and finally, the cute little sign-off: this one comes from ./drivers/usb/gadget/udc, dated October 2026, and it's ep_write_UDCCSR(9) all day long 🌈🎀