pch_udc_ep_fifo_flush(9)

💅 pch_udc_ep_fifo_flush — the Kernel API Manual, but make it make sense

okay so bestie, settle in, because this one is a tiny little function with a big job. It's a <purple>kernel API</purple> page — the kind that lives in section 9 of the manual, iykyk — and the whole vibe is: flush the endpoint fifo. That's it. That's the name. pch_udc_ep_fifo_flush. Slay.

✨ SYNOPSIS ✨

void pch_udc_ep_fifo_flush (struct pch_udc_ep *ep , int dir );

literally that's the whole signature, no cap. returns void, so she's not giving you anything back — she just does the thing. 🫶

🎀 ARGUMENTS 🎀

• ep — a reference to a structure of type pch_udc_ep_regs. (And yes, the synopsis up there says struct pch_udc_ep — I'm just the messenger, quoting the page exactly, don't come for me 🙈)
• dir — the direction of the endpoint. <hotpink>0</hotpink> = the endpoint is OUT. <hotpink>!0</hotpink> = the endpoint is IN. That !0 is doing so much heavy lifting for "anything that isn't zero," honestly iconic.

🌈 SEE ALSO 🌈

okay this is the part where the page goes full main-character and lists, like, the entire friend group. every single one, bestie, in order, zero skips 💖

Kernel file ./drivers/usb/gadget/udc/pch_udc.c struct pch_udc_data_dma_desc(9), struct pch_udc_stp_dma_desc(9), struct pch_udc_cfg_data(9), struct pch_udc_ep(9), struct pch_vbus_gpio_data(9), struct pch_udc_dev(9), struct pch_udc_request(9), pch_udc_csr_busy(9), pch_udc_write_csr(9), pch_udc_read_csr(9), pch_udc_rmt_wakeup(9), pch_udc_get_frame(9), pch_udc_clear_selfpowered(9), pch_udc_set_selfpowered(9), pch_udc_set_disconnect(9), pch_udc_clear_disconnect(9), pch_udc_reconnect(9), pch_udc_vbus_session(9), pch_udc_ep_set_stall(9), pch_udc_ep_clear_stall(9), pch_udc_ep_set_trfr_type(9), pch_udc_ep_set_bufsz(9), pch_udc_ep_set_maxpkt(9), pch_udc_ep_set_subptr(9), pch_udc_ep_set_ddptr(9), pch_udc_ep_set_pd(9), pch_udc_ep_set_rrdy(9), pch_udc_ep_clear_rrdy(9), pch_udc_set_dma(9), pch_udc_clear_dma(9), pch_udc_set_csr_done(9), pch_udc_disable_interrupts(9), pch_udc_enable_interrupts(9), pch_udc_disable_ep_interrupts(9), pch_udc_enable_ep_interrupts(9), pch_udc_read_device_interrupts(9), pch_udc_write_device_interrupts(9), pch_udc_read_ep_interrupts(9), pch_udc_write_ep_interrupts(9), pch_udc_read_device_status(9), pch_udc_read_ep_control(9), pch_udc_clear_ep_control(9), pch_udc_read_ep_status(9), pch_udc_clear_ep_status(9), pch_udc_ep_set_nak(9), pch_udc_ep_clear_nak(9), pch_udc_ep_enable(9), pch_udc_ep_disable(9), pch_udc_wait_ep_stall(9), pch_udc_init(9), pch_udc_exit(9), pch_udc_pcd_get_frame(9), pch_udc_pcd_wakeup(9), pch_udc_pcd_selfpowered(9), pch_udc_pcd_pullup(9), pch_udc_pcd_vbus_session(9), pch_udc_pcd_vbus_draw(9), pch_vbus_gpio_get_value(9), pch_vbus_gpio_work_fall(9), pch_vbus_gpio_work_rise(9), pch_vbus_gpio_irq(9), pch_vbus_gpio_init(9), pch_vbus_gpio_free(9), complete_req(9), empty_req_queue(9), pch_udc_free_dma_chain(9), pch_udc_create_dma_chain(9), prepare_dma(9), process_zlp(9), pch_udc_start_rxrequest(9), pch_udc_pcd_ep_enable(9), pch_udc_pcd_ep_disable(9), pch_udc_alloc_request(9), pch_udc_free_request(9), pch_udc_pcd_queue(9), pch_udc_pcd_dequeue(9), pch_udc_pcd_set_halt(9), pch_udc_pcd_set_wedge(9), pch_udc_pcd_fifo_flush(9), pch_udc_init_setup_buff(9), pch_udc_start_next_txrequest(9), pch_udc_complete_transfer(9), pch_udc_complete_receiver(9), pch_udc_svc_data_in(9), pch_udc_svc_data_out(9), pch_udc_svc_control_in(9), pch_udc_svc_control_out(9), pch_udc_postsvc_epinters(9), pch_udc_read_all_epstatus(9), pch_udc_activate_control_ep(9), pch_udc_svc_ur_interrupt(9), pch_udc_svc_enum_interrupt(9), pch_udc_svc_intf_interrupt(9), pch_udc_svc_cfg_interrupt(9), pch_udc_dev_isr(9), pch_udc_isr(9), pch_udc_setup_ep0(9), pch_udc_pcd_reinit(9), pch_udc_pcd_init(9), init_dma_pools(9)

whew. that's the whole roster. took a breath for you. 🌸

heads up bestie: if you got here looking for the description of what it does beyond "flush the endpoint fifo" — so did I. the page is short and mysterious and that's her vibe. 💀

and that's the whole page, fr fr. this masterpiece lives over in ./drivers/usb/gadget/udc, dated October 2026, coming to you courtesy of the Kernel API Manual. go forth and flush responsibly, bestie — you ate 👑✨🦋