4.6 KiB
4.6 KiB
Current state
Where the code is right now
The committed tree is the X520 product implementation: AF_PACKET datapath with read-time rate buckets and the backward excess-fill smear (nics/x520/ — rate is a headline, never a verdict; smearWindow 4 buckets = 64 ms display latency, resize after measuring the stall distribution), the mixed FS+Wiitek diagnostics with the BCM ECD length path, testDriver = ixgbe. No hardware-timestamp machinery anywhere. The CX-5 is retired (nics/connectx-5/, "Status") and the E810 bit-bang investigation with it (nics/e810/).
Every parked experiment is distilled into docs and its code dropped — no stashes, nothing outside the repo: the AF_XDP conversion in xdp.md, the CX-5 Wiitek-pair implementation in nics/connectx-5/ (including the MCIA gateway constants), the phydiag campaign across nics/e810/, nics/x710/, modules/fs/ and modules/fibergaga/.
The box
- Single usable PCIe slot (Gen4 x8): holds the X520-DA2 (dual SFP+). Verify 5 GT/s ×8 trained at bringup (
lspci -vv). The ConnectX-5 is out of the box. - X710 on a CPU x4 port (Gen3 x4, ~31.5 Gbps/dir — enough for 2×10G full duplex despite the driver's worst-case bandwidth warning).
- Many CPU cores; goroutine-heavy designs welcome.
- mstflint (AUR — not in the Arch repos) provides
mstlink/mstreg/mstconfigfor the CX-5, if it ever returns.
| Interface | Device | Role (rules: hardware.md) |
|---|---|---|
enp1s0f0 + second port |
X520 (ixgbe) | Test pair — FS + Wiitek, dispatched by EEPROM PN so either port may hold either module. Stock ixgbe refuses the FS's honest EEPROM and its port has no netdev until ./load-ixgbe (allow_unsupported_sfp=1 + the sff_i2c/ETQF patches); the tool needs exactly 2 ixgbe interfaces |
enp3s0f0np0 / enp3s0f1np1 |
X710 (i40e) | Unused by the tool (was the noise pair; alien crosstalk measured ineffective — measurement.md). Two Wiiteks still seated (has been enp4s0f* across reboots). The FS cannot live here (firmware rejects the honest EEPROM, no allow_unsupported_sfp in i40e) |
enp88s0 |
igc | LAN uplink, default route; sibling enp89s0 is dark |
Hardware
| Item | Status | Notes |
|---|---|---|
| X520-DA2 | Installed in the single PCIe slot — the product NIC (nics/x520/) | Unmediated bit-bang I2C (patched-ixgbe sff_i2c), <25 ms RollBall, FS links and the ECD length path is proven; the smoothed-bucket rate design removes the need for hardware RX stamps |
| ConnectX-5 | Out of the box — retired | Ran the two-Wiitek pair at near line rate with dual-end SNR (MCIA transport, recorded with its gateway constants in nics/connectx-5/), but the firmware quantizes every module mailbox read to ~150 ms steps and the FS never links behind mlx5 — nics/connectx-5/, "Status" |
| FS SFP-10G-T-100 ×2 | One in the X520 test pair, one on the shelf | BCM84891L, documented, robust; ixgbe-only (unlinkable behind mlx5 — host-interface deadlock, confirmed module-typed, nics/connectx-5/ — and rejected by the X710). The FS+Wiitek mixed pair (FS length via ECD + Wiitek SNR) is the product configuration |
| Replacement Wiiteks | One in the X520 test pair, two seated in the unused X710, rest on the shelf | Originals bricked by register exploration — modules/wiitek/ trap first. IEEE-standard registers only (modules/README.md safe set); VCT templates are single-shot candidates on a sacrificial unit only |
| Fibergaga SFP-10G-T-30M | On the shelf | Aquantia, RollBall, the documented oracle; the alternate length path if the pair mix ever changes |
| 10Gtek | In hand | Claims SFP-10G-SR, still copper RJ45; filler, not in the test set |
| E810 | Out of the box | Patched ice + sff_i2c remains useful only if it returns for read-side work |
Bench driver
- Patched ixgbe, bench build (
kernel/ixgbe-sff/, full driver source tracked; build artifacts gitignored) — out-of-tree module for the dev host: the product patch plus the bench-only extras (reg_opsvalue readback,ts_bench);./load-ixgberebuilds + swaps the module withallow_unsupported_sfp=1. The product subset (raw I2C +sff_i2c, ETQF steering, FCoE slot guard) is versioned atkernel/ixgbe-sff.patchand applied by./mkimageto every appliance kernel build — apply fails loudly when stable moves under it; port the patch then. Details: nics/x520/.
Every boot
./load-ixgbe— until then the FS port has no netdev (stock driver, error -95) anddriverPair("ixgbe")cannot find 2 interfaces. cabletest's BOOT check names the condition (patched ixgbefails when any bound port lackssff_i2c).- Re-apply host tuning (hardware.md) before trusting results.