usb_ep_fifo_flush(9)

🦋 usb_ep_fifo_flush(9) 🦋

okay so this page is fresh out of the Kernel API Manual, and it's about usb_ep_fifo_flush — a tiny function with big “clean up that mess” energy. 💅

✨ NAME ✨

usb_ep_fifo_flush — flushes contents of a fifo. that's it, that's the whole name, slay.

🌸 SYNOPSIS 🌸

void usb_ep_fifo_flush (struct usb_ep *ep );

🎀 ARGUMENTS 🎀

• ep — the endpoint whose fifo is being flushed. like, the specific endpoint bestie, not a random one.

💖 DESCRIPTION 💖

okay so here's the vibe: this call may be used to flush the "unclaimed data" that may exist in an endpoint fifo after abnormal transaction terminations. it's the little cleanup era for leftover fifo data. 🧚

bestie, read this twice: the call must never be used except when the endpoint is not being used for any protocol translation. not “usually”, not “mostly” — never except that case. periodt. 🚨

and good news for your interrupt-brain: this routine may be called in interrupt context. no cap. ⚡

🌈 SEE ALSO 🌈

go read these too, iykyk:

• Kernel file ./drivers/usb/gadget/udc/core.c
• struct usb_udc(9)
• usb_ep_set_maxpacket_limit(9)
• usb_ep_enable(9)
• usb_ep_disable(9)
• usb_ep_alloc_request(9)
• usb_ep_free_request(9)
• usb_ep_queue(9)
• usb_ep_dequeue(9)
• usb_ep_set_halt(9)
• usb_ep_clear_halt(9)
• usb_ep_set_wedge(9)
• usb_ep_fifo_status(9)
• usb_gadget_frame_number(9)
• usb_gadget_wakeup(9)
• usb_gadget_set_remote_wakeup(9)
• usb_gadget_set_selfpowered(9)
• usb_gadget_clear_selfpowered(9)
• usb_gadget_vbus_connect(9)
• usb_gadget_vbus_draw(9)
• usb_gadget_vbus_disconnect(9)
• usb_gadget_connect(9)
• usb_gadget_disconnect(9)
• usb_gadget_deactivate(9)
• usb_gadget_activate(9)
• usb_gadget_giveback_request(9)
• gadget_find_ep_by_name(9)
• usb_gadget_check_config(9)
• usb_udc_vbus_handler(9)
• usb_gadget_udc_reset(9)
• usb_gadget_udc_start_locked(9)
• usb_gadget_udc_stop_locked(9)
• usb_gadget_udc_set_speed(9)
• usb_gadget_enable_async_callbacks(9)
• usb_gadget_disable_async_callbacks(9)
• usb_udc_release(9)
• usb_initialize_gadget(9)
• usb_add_gadget(9)
• usb_add_gadget_udc_release(9)
• usb_get_gadget_udc_name(9)
• usb_add_gadget_udc(9)
• usb_del_gadget(9)
• usb_del_gadget_udc(9)

okay that's the page, bestie. source: ./drivers/usb/gadget/udc, October 2026. mwah 💋✨