pch_udc_create_dma_chain(9)

🫶 pch_udc_create_dma_chain(9) 💖

okay so bestie, welcome to the Kernel API Manual entry for pch_udc_create_dma_chain(9) — the DMA-chain creator/reinitializer that is lowkey iconic. Pull up a chair, hydrate, and let’s get into it. ✨

---

🌸 NAME 🌸

pch_udc_create_dma_chain — literally this function creates or reinitializes a DMA chain. That’s the whole vibe: make a chain or refresh one, periodt. 💅

---

🦋 SYNOPSIS 🦋

int pch_udc_create_dma_chain (struct pch_udc_ep *ep , struct pch_udc_request *req , unsigned long buf_len , gfp_t gfp_flags );

---

🎀 ARGUMENTS 🎀

• ep — Reference to the endpoint structure. The endpoint struct is the moment. 🫶
• req — Reference to the request. Your request, your rules. 💅
• buf_len — The buffer length. Yes, the length of the buffer, no cap. 📏
• gfp_flags — Flags to be used while mapping the data buffer. Mapping flags only, bestie. 🗺️

---

💜 DESCRIPTION 💜

Return codes: okay so here’s the tea:

• 0 — success. Slay. 👑
• -ENOMEM — dma_pool_alloc invocation fails. Not the vibe, but now you know. 😭

---

🌈 SEE ALSO 🌈

Kernel file ./drivers/usb/gadget/udc/pch_udc.c plus the entire friend group — no cap, every single one is here:

• 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_fifo_flush(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)
• 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)

---

mwah 💋 this page was brought to you by ./drivers/usb/gadget/udc, dated October 2026, and starring pch_udc_create_dma_chain(9). Catch you in the next manpage, bestie — periodt. 🫶✨