xudc_read_fifo(9)

💖 xudc_read_fifo(9) — from the Kernel API Manual 💖

okay so bestie, this is the page for xudc_read_fifo, and it's literally the little function that reads the data from the given endpoint buffer. come sit with me, we're doing a full vibe check. 🫶

✨ NAME ✨

xudc_read_fifo — reads the data from the given endpoint buffer. no cap, that's the whole name. iconic behavior. 💅

🌸 SYNOPSIS 🌸

int xudc_read_fifo (struct xusb_ep *ep , struct xusb_req *req );

🎀 ARGUMENTS 🎀

• ep — pointer to the usb device endpoint structure. think of it as the endpoint's little profile card. 💖
• req — pointer to the usb request structure. it's the request that's the main character of this read. ✨

🔥 RETURN 🔥

• 0 if request is completed.
• -EAGAIN if not completed.

that's the whole mood: completed gets a 0, and not completed gets -EAGAIN. fr fr, the way that return value is keeping it real. 😭

🦋 DESCRIPTION 🦋

Pulls OUT packet data from the endpoint buffer. yes, OUT in all caps, because that's the direction and we respect it. it's giving "data, please leave the endpoint buffer." 💅

🌈 SEE ALSO 🌈

• Kernel file: ./drivers/usb/gadget/udc/udc-xilinx.c
• struct xusb_req(9)
• struct xusb_ep(9)
• struct xusb_udc(9)
• xudc_write32(9)
• xudc_read32(9)
• xudc_write32_be(9)
• xudc_read32_be(9)
• xudc_wrstatus(9)
• xudc_epconfig(9)
• xudc_start_dma(9)
• xudc_dma_send(9)
• xudc_dma_receive(9)
• xudc_eptxrx(9)
• xudc_done(9)
• xudc_write_fifo(9)
• xudc_nuke(9)
• xudc_ep_set_halt(9)
• __xudc_ep_enable(9)
• xudc_ep_enable(9)
• xudc_ep_disable(9)
• xudc_ep_alloc_request(9)
• xudc_free_request(9)
• __xudc_ep0_queue(9)
• xudc_ep0_queue(9)
• xudc_ep_queue(9)
• xudc_ep_dequeue(9)
• xudc_ep0_enable(9)
• xudc_ep0_disable(9)
• xudc_get_frame(9)
• xudc_wakeup(9)
• xudc_pullup(9)
• xudc_eps_init(9)
• xudc_stop_activity(9)
• xudc_start(9)
• xudc_stop(9)
• xudc_clear_stall_all_ep(9)
• xudc_startup_handler(9)
• xudc_ep0_stall(9)
• xudc_setaddress(9)
• xudc_getstatus(9)
• xudc_set_clear_feature(9)
• xudc_handle_setup(9)
• xudc_ep0_out(9)
• xudc_ep0_in(9)
• xudc_ctrl_ep_handler(9)
• xudc_nonctrl_ep_handler(9)
• xudc_irq(9)
• xudc_probe(9)
• xudc_remove(9)

mwah 💋 this page is from the Kernel API Manual, the source/version is ./drivers/usb/gadget/udc, it's dated October 2026, and xudc_read_fifo(9) is signing off. periodt. 👑