STRUCT FW_CDEV_SEND_REQUEST(9)

💖 struct fw_cdev_send_request 💖

okay bestie, this is the Kernel API Manual page for struct fw_cdev_send_request — the struct for sending an asynchronous request packet. it's giving lowkey legendary kernel-struct energy, and we're gonna go through every single field together 🦋✨

✨ NAME ✨

struct fw_cdev_send_request — Send an asynchronous request packet. periodt 💅

🌸 SYNOPSIS 🌸

       struct fw_cdev_send_request {
           __u32 tcode;
           __u32 length;
           __u64 offset;
           __u64 closure;
           __u64 data;
           __u32 generation;
        };

🎀 Members 🎀

the cast of fields, no skips:

• tcode — Transaction code of the request.
• length — Length of outgoing payload, in bytes.
• offset — 48-bit offset at destination node.
• closure — Passed back to userspace in the response event.
• data — Userspace pointer to payload.
• generation — The bus generation where packet is valid.

💜 DESCRIPTION 💜

okay so basically: you send a request to the device, and this ioctl implements all outgoing requests. Both quadlet and block request specify the payload as a pointer to the data in the data field. Once the transaction completes, the kernel writes either fw_cdev_event_response event or fw_cdev_event_response event back. The closure field is passed back to user space in the response event. that's the tea ☕✨

🔥 SEE ALSO 🔥

the related squad, all of it, no cap:

• Kernel file ./include/uapi/linux/firewire-cdev.h
• struct fw_cdev_event_common(9)
• struct fw_cdev_event_bus_reset(9)
• struct fw_cdev_event_response(9)
• struct fw_cdev_event_response2(9)
• struct fw_cdev_event_request(9)
• struct fw_cdev_event_request2(9)
• struct fw_cdev_event_request3(9)
• struct fw_cdev_event_iso_interrupt(9)
• struct fw_cdev_event_iso_interrupt_mc(9)
• struct fw_cdev_event_iso_resource(9)
• struct fw_cdev_event_phy_packet(9)
• struct fw_cdev_event_phy_packet2(9)
• union fw_cdev_event(9)
• struct fw_cdev_get_info(9)
• struct fw_cdev_send_response(9)
• struct fw_cdev_allocate(9)
• struct fw_cdev_deallocate(9)
• struct fw_cdev_initiate_bus_reset(9)
• struct fw_cdev_add_descriptor(9)
• struct fw_cdev_remove_descriptor(9)
• struct fw_cdev_create_iso_context(9)
• struct fw_cdev_set_iso_channels(9)
• struct fw_cdev_iso_packet(9)
• struct fw_cdev_queue_iso(9)
• struct fw_cdev_start_iso(9)
• struct fw_cdev_stop_iso(9)
• struct fw_cdev_flush_iso(9)
• struct fw_cdev_get_cycle_timer(9)
• struct fw_cdev_get_cycle_timer2(9)
• struct fw_cdev_allocate_iso_resource(9)
• struct fw_cdev_send_stream_packet(9)
• struct fw_cdev_send_phy_packet(9)
• struct fw_cdev_receive_phy_packets(9)

mwah 💖 that's the whole page, bestie. source/version: ./include/uapi/linux; date: October 2026; manual name: Kernel API Manual; footer title: struct fw_cdev_send_request(9). slay and goodbye 🫶🌈💅