STRUCT V4L2_ASYNC_CONNECTION(9)

💅 NAME 💅

struct v4l2_async_connection — the sub-device connection descriptor, as known to a bridge 🫶

okay so real quick, this page is literally struct v4l2_async_connection(9) from the Kernel API Manual and it's giving "small struct, big responsibilities." let's get into it ✨

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🎀 SYNOPSIS 🎀

struct v4l2_async_connection {
    struct v4l2_async_match_desc match;
    struct v4l2_async_notifier *notifier;
    struct list_head asc_entry;
    struct list_head asc_subdev_entry;
    struct v4l2_subdev *sd;
 };

no cap, that's the whole thing. five members. iconic. 👑

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🌸 Members 🌸

• match — the struct of match type plus all the per-bus type matching data sets. this is the "who are we even looking for" part of the vibe check 🦋
• notifier — the async notifier that this connection is related to. bestie, it knows its people 💖
• asc_entry — used to add struct v4l2_async_connection objects to the notifier's waiting_list or done_list. yes, both. it's versatile like that ✨
• asc_subdev_entry — an entry in the struct v4l2_async_subdev.asc_list list. lowkey just a list hookup 🎀
• sd — the related sub-device. the main character this whole struct is simping for 😭

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🦋 Description 🦋

okay this is the one rule you actually have to remember, bestie, so pay attention 💅

when this struct gets used as a member inside a driver-specific struct, the driver-specific struct shall contain struct v4l2_async_connection as its first member. first. as in position zero. as in no skipping ahead. it's giving "this is the foundation, everything else stacks on top of it" 🧚

literally do not put it anywhere else. first member. that's the assignment, periodt. 🔥

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🌈 SEE ALSO 🌈

all the sister pages and friends-of-the-family, in no particular order, but every single one because we don't leave anyone out at this function's birthday party 🎉

Kernel file ./include/media/v4l2-async.h, enum v4l2_async_match_type(9), struct v4l2_async_match_desc(9), struct v4l2_async_notifier_operations(9), struct v4l2_async_notifier(9), struct v4l2_async_subdev_endpoint(9), v4l2_async_debug_init(9), v4l2_async_nf_init(9), v4l2_async_subdev_nf_init(9), v4l2_async_nf_add_fwnode(9), v4l2_async_nf_add_fwnode_remote(9), v4l2_async_nf_add_i2c(9), v4l2_async_subdev_endpoint_add(9), v4l2_async_connection_unique(9), v4l2_async_nf_register(9), v4l2_async_nf_unregister(9), v4l2_async_nf_cleanup(9), v4l2_async_register_subdev(9), v4l2_async_register_subdev_sensor(9), v4l2_async_unregister_subdev(9)

like, go read those too. iykyk 👀

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✨ and that's a wrap on struct v4l2_async_connection(9), brought to you from ./include/media, dated October 2026, with the header label struct v4l2_...c_connection(9) because terminal column widths are haters 💀 anyway ily, go write that driver struct correctly, mwah 🫶💖🎀