i40e_pf_loop_reset(9)

📦 version 7.3.1, in nixpkgs unstable

💅 i40e_pf_loop_reset(9) — bestie's guide to the reset-in-a-loop situation

okay so this is a page from the Kernel API Manual, and no cap, it's lowkey one of the most "wait, WHAT?" functions in the whole i40e driver. sit down, grab a 🍓, we're learning about firmware having a full meltdown.

✨ NAME ✨

i40e_pf_loop_reset — bestie, it literally just performs a reset in a loop. that's the whole vibe. 🔁

🌸 SYNOPSIS 🌸

int i40e_pf_loop_reset (struct i40e_pf *pf );

🎀 ARGUMENTS 🎀

  • pf — the board private structure. the main character of this whole saga. 🫶

💖 DESCRIPTION 💖

so here's the situation, and it's giving chaos.

This function is the move when a NIC is about to enter recovery mode. and why would a NIC do that? because when a NIC's internal data structures get corrupted, its firmware is gonna enter recovery mode. that's just the prophecy. 🔮

here's the timeline that makes everyone stressed: right after a POR, it takes about 7 minutes for the firmware to enter recovery mode. seven. whole. minutes. 😭 and until that time, the NIC is just sort of... in some kind of intermediate state. hanging out. existing. unhelpfully. After that time period though, the NIC almost surely enters recovery mode.

and the only way a driver can detect that intermediate state is to issue a series of pf-resets and check the return value. that's it. that's the whole detector. so iconic of the hardware to make us do this.

⭐ important detail bestie: if a PF reset returns success, the firmware could be in recovery mode, so whoever called this code needs to check for recovery mode if this function returns success. don't skip that. i'm serious. 🙈

There is a little chance that firmware will hang in intermediate state forever — like, no thoughts, head empty, forever — and since waiting 7 minutes is quite a lot of time, this function waits 10 seconds and then gives up by returning an error. it's not a quitter, it just has boundaries. periodt. 💅

Returns 0 on success, negative on failure.

🦋 SEE ALSO 🦋

first up, the kernel file itself:

  • Kernel file ./drivers/net/ethernet/intel/i40e/i40e_main.c

and now, the entire extended friend group (iykyk). every single one of these is real:

like... that's the whole driver. every single one. no cap. 👑

🌈 and that's the page bestie!! mwah 💖

sign-off: this little masterpiece lives under ./drivers/net/ethernet/intel/i40e and was written down in October 2026 — and yes, it's page i40e_pf_loop_reset(9) of the Kernel API Manual, so cite it properly, periodt. 🎀🦋

📦 where this page comes from