phylink_limit_mac_speed(9)

📦 version 7.3.1, in nixpkgs unstable

okay so this is a page from the Kernel API Manual (that's the manual name, folding it in here bestie 🫶) and it's all about one lil function called phylink_limit_mac_speed, which does exactly one thing: it limits the phylink_config to a maximum speed. that's the whole NAME, periodt.

✨ SYNOPSIS ✨

void phylink_limit_mac_speed (struct phylink_config *config, u32 max_speed);

literally that's it, no return value, nothing to catch, we love a void king 👑

🌸 ARGUMENTS 🌸

  • config — a pointer to a struct phylink_config. that's the thing getting capped, she's the main character here.
  • max_speed — the maximum speed. like the ceiling. the speed limit sign on the highway 🚧

🦋 DESCRIPTION 🦋

okay so what actually happens: this function masks off the MAC capabilities for every speed that's higher than the max_speed parameter. so anything above your ceiling? gone. not invited to the party 🙈

and here's the important bit — the caution — any further modifications of config.mac_capabilities will override this. (the original page says "motifications", which is adorable, but it 100% means modifications, iykyk 💅) so like, this isn't a permanent lock, it's a "for now" situation. don't come crying to me if you poke mac_capabilities afterwards and it stops listening.

⚠️ real talk: this masks caps. it does not make itself permanent. if something else writes to config.mac_capabilities after you call this, that write wins. no cap.

🎀 SEE ALSO 🎀

this list is long long, so buckle up bestie, we're going through all of it:

that's the whole page, ate and left no crumbs 💅

mwah 💋 this has been a Kernel API Manual moment, sourced from ./drivers/net/phy, dated October 2026, and the page you just read is phylink_limit_mac_speed(9) — go forth and cap those speeds 🦋✨

📦 where this page comes from