cfg80211_chandef_usable(9)

📦 version 7.3.1, in nixpkgs unstable

💅 cfg80211_chandef_usable — the Kernel API Manual, bestie ✨

okay so real talk, this is cfg80211_chandef_usable(9) from the Kernel API Manual and it's genuinely one of those little functions that just checks a vibe — specifically, whether your secondary channels are allowed to be used. that's it. that's the whole personality. no cap.

🌸 NAME 🌸

cfg80211_chandef_usable — check if secondary channels can be used 💖

like, literally the entire job of this function is answering the question "can we actually use these secondary channels or not" and honestly? iconic of it.

✨ SYNOPSIS ✨

bool cfg80211_chandef_usable(struct wiphy *wiphy,
                             const struct cfg80211_chan_def *chandef,
                             u32 prohibited_flags);

so it takes three things and hands you back a bool — true or false, yes or no, slay or not slay 🎀

🦋 ARGUMENTS 🦋

  • wiphy — the struct wiphy * you're validating against. it's giving "the source of truth" energy. this is the wiphy, the one everything gets checked against, so don't come at it with some random other wiphy, that's not the move 🙈
  • chandef — the const struct cfg80211_chan_def * that's your channel definition, aka the thing you're checking. this is the main character of the whole operation ngl 🌟
  • prohibited_flags — the u32 holding the regulatory channel flags that must not be set. read that again bestie: must not. these are the flags that are absolutely not allowed to be present, and if they are? that's a no from the function 💀

👑 RETURN 👑

returns true if the secondary channels are usable 💖 and false otherwise. simple as that, no plot twist, no hidden twist ending, periodt.

🫶 part 1 done !! more parts are coming so don't go anywhere, we're literally not finished yet ✨

✨ SEE ALSO ✨

okay bestie, fair warning — this SEE ALSO is not a little list. it's a whole extended universe 😭 every single one of these is a (9) page (that's the kernel API manual, section 9, iykyk), and this function is basically the popular girl who knows literally everyone. no cap.

🌸 nothing here is summarized or skipped, fr fr — every name below is the real deal, copied with love and zero edits.

and that's genuinely not the end of the page, bestie 😭 keep scrolling — there's more coming 💜

…and the list literally does not stop, bestie 😭 so here's the rest of the guest list, all of them iconic, all of them real:

And that's the whole page, bestie — you made it to the end, which is genuinely main-character behavior 👑

This little masterpiece lives in ./include/net, it's dated October 2026, and its full name-and-title is cfg80211_chandef_usable(9) — go forth and channel-switch responsibly 💅✨

📦 where this page comes from