dwc2_hc_start_transfer_ddma(9)

💅 dwc2_hc_start_transfer_ddma — a kernel API moment (section 9, bestie)

okay so we're in the dwc2_hc_start_transfer_ddma(9) page, from the Kernel API Manual, and it's literally about setting up a host channel data transfer and kicking it off in Descriptor DMA mode. slay. let's get into it 🎀

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✨ NAME ✨

dwc2_hc_start_transfer_ddma — does the setup for a data transfer for a host channel and starts the transfer in Descriptor DMA mode. no cap, that's the whole gig 🦋

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🌸 SYNOPSIS 🌸

void dwc2_hc_start_transfer_ddma (struct dwc2_hsotg *hsotg , struct
dwc2_host_chan *chan );

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💖 ARGUMENTS 💖

• hsotg — the programming view of the DWC_otg controller. that's your main character struct fr 👑
• chan — the info needed to initialize the host channel. everything it needs to get cute and set up 🫶

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🌈 DESCRIPTION 🌈

So first thing: it initializes the HCTSIZ register. iconic. for a PING transfer, the Do Ping bit gets set — yes, that's the actual name, iykyk 💅

Then it sets the PID and NTD values. and for periodic transfers it initializes the SCHED_INFO field with the micro-frame bitmap ✨

After that comes the HCDMA register — it gets initialized with the descriptor list address and the CTD value, and then the transfer is started by enabling the channel. and that's the moment, bestie, the transfer is live 🔥

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🦋 SEE ALSO 🦋

the kernel file is ./drivers/usb/dwc2/hcd.c and it's giving a whole friend group, so let's list every single one, no skipping 👑

• dwc2_enable_common_interrupts(9)
• dwc2_enable_host_interrupts(9)
• dwc2_disable_host_interrupts(9)
• dwc2_calc_frame_interval(9)
• dwc2_read_packet(9)
• dwc2_dump_channel_info(9)
• dwc2_hc_init(9)
• dwc2_hc_halt(9)
• dwc2_hc_cleanup(9)
• dwc2_hc_set_even_odd_frame(9)
• dwc2_hc_write_packet(9)
• dwc2_hc_do_ping(9)
• dwc2_hc_start_transfer(9)
• dwc2_hc_continue_transfer(9)
• dwc2_hcd_start(9)
• dwc2_hcd_connect(9)
• dwc2_hcd_disconnect(9)
• dwc2_hcd_rem_wakeup(9)
• dwc2_hcd_stop(9)
• dwc2_core_init(9)
• dwc2_core_host_init(9)
• dwc2_assign_and_init_hc(9)
• dwc2_hcd_select_transactions(9)
• dwc2_queue_transaction(9)
• dwc2_hcd_queue_transactions(9)
• dwc2_port_suspend(9)
• dwc2_port_resume(9)
• dwc2_host_get_tt_info(9)
• dwc2_host_put_tt_info(9)
• dwc2_backup_host_registers(9)
• dwc2_restore_host_registers(9)
• dwc2_host_enter_hibernation(9)
• dwc2_host_enter_partial_power_down(9)
• dwc2_host_enter_clock_gating(9)
• dwc2_host_exit_clock_gating(9)

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bestie this page is from ./drivers/usb/dwc2, dated October 2026, and it's literally called dwc2_hc_start_transfer_ddma(9). that's the whole sign-off, mwah 💋✨ go read the source, ily 🧚💜