ixgbe: add 10GBase-T SFP+ module support when allow_unsupported_sfp is set

10GBASE-T-SFP-FIX.md

@@ -0,0 +1,180 @@
+# Fix: 10GBase-T SFP+ Module Support for Intel ixgbe (82599/X520/X540)
+
+## The Problem
+
+10GBase-T SFP+ modules (copper RJ45 transceivers) are rejected by the Intel ixgbe driver with:
+
+```
+ixgbe: SFP+ module not supported
+```
+
+This happens even with `allow_unsupported_sfp=1` set.
+
+### Root Cause
+
+The SFF-8472 standard defines compliance code bits in byte 0x03 (`comp_codes_10g`) only for fiber optic types:
+
+| Bit | Type |
+|-----|------|
+| 0x10 | 10GBASE-SR |
+| 0x20 | 10GBASE-LR |
+| 0x40 | 10GBASE-LRM |
+| 0x80 | 10GBASE-ER |
+
+**10GBase-T has no bit defined.** Copper RJ45 SFP+ modules report `comp_codes_10g = 0x00`.
+
+The ixgbe driver checks `comp_codes_10g` early in `ixgbe_identify_sfp_module_generic()` and rejects modules with `comp_codes_10g == 0` **before** the `allow_unsupported_sfp` flag is ever consulted. This makes the kernel parameter useless for 10GBase-T modules.
+
+## The Fix
+
+A 4-line patch (+ comments) in `src/ixgbe_phy.c` that detects 10GBase-T modules and forces SR classification when `allow_unsupported_sfp` is explicitly enabled:
+
+```c
+if (comp_codes_10g == 0 && cable_tech == 0 &&
+    hw->allow_unsupported_sfp) {
+    comp_codes_10g = IXGBE_SFF_10GBASESR_CAPABLE;
+}
+```
+
+The conditions `comp_codes_10g == 0 && cable_tech == 0` specifically identify modules that are neither fiber nor DAC (direct attach copper), which matches 10GBase-T transceivers. The fix only activates when `allow_unsupported_sfp` is explicitly enabled by the administrator.
+
+## Tested Hardware
+
+| Component | Model |
+|-----------|-------|
+| Server | Dell PowerEdge R630 |
+| NIC | Dell C63DV rNDC (Intel X520 / 82599 SFI, 2x SFP+) |
+| SFP+ Module | FS.com SFP-10GM-T-30 (10GBase-T, Dell-coded) |
+| OS | Proxmox Backup Server 3.3-1, kernel 6.17.2-1-pve |
+
+**Result:** Link established at 10 Gbps Full Duplex, 0.13ms latency.
+
+This fix should work with any 10GBase-T SFP+ module in any Intel 82599-based NIC (X520, X540 with SFP+ slots, etc.).
+
+## Prerequisites
+
+### 1. EEPROM Vendor Lock Bypass (Dell/HP/Lenovo servers only)
+
+Brand-locked servers reject non-OEM SFP+ modules at the EEPROM level. The SFP+ module's EEPROM byte 0x58 (Enhanced Options) must include the ALLOW_ANY_SFP bit.
+
+If your module is already vendor-coded for your server brand, skip this step.
+
+To check and patch (requires `ethtool` or `i2cset`):
+```bash
+# Read current value (via a working NIC that can see the module)
+ethtool -m <interface> offset 0x58 length 1
+
+# Patch to 0xfd (sets ALLOW_ANY_SFP bit)
+# WARNING: This modifies the SFP+ module's EEPROM permanently
+i2cset -y <bus> 0x50 0x58 0xfd
+```
+
+### 2. Enable allow_unsupported_sfp
+
+```bash
+# Persistent via modprobe
+echo 'options ixgbe allow_unsupported_sfp=1' > /etc/modprobe.d/ixgbe.conf
+
+# Also in GRUB (belt and suspenders)
+# Add to GRUB_CMDLINE_LINUX in /etc/default/grub:
+#   ixgbe.allow_unsupported_sfp=1
+# Then: update-grub
+```
+
+## Build & Install
+
+### Debian/Ubuntu/Proxmox
+
+```bash
+# Install dependencies
+apt update
+apt install -y build-essential dkms linux-headers-$(uname -r) libdw-dev
+# For Proxmox: apt install -y proxmox-headers-$(uname -r) instead of linux-headers
+
+# Clone this repo
+git clone https://github.com/FilleMang/ethernet-linux-ixgbe.git
+cd ethernet-linux-ixgbe
+
+# Build
+cd src
+make clean
+make CFLAGS_EXTRA="-DDISABLE_PCI_AER" install
+
+# Update initramfs so the patched driver loads at boot
+update-initramfs -u
+
+# Load the new driver
+modprobe -r ixgbe && modprobe ixgbe allow_unsupported_sfp=1
+```
+
+### Apply Patch Only (if you already have Intel OOT source)
+
+```bash
+cd ethernet-linux-ixgbe
+git apply patches/0001-ixgbe-add-10GBase-T-SFP-support.patch
+```
+
+Or using `patch`:
+```bash
+patch -p1 < patches/0001-ixgbe-add-10GBase-T-SFP-support.patch
+```
+
+## Verification
+
+```bash
+# Check driver version (should show 6.3.4)
+modinfo ixgbe | grep version
+
+# Check module is from updates/ (not kernel built-in)
+modinfo ixgbe | grep filename
+# Expected: /lib/modules/.../updates/drivers/net/ethernet/intel/ixgbe/ixgbe.ko
+
+# Check link status
+ethtool eno1
+# Expected: Speed: 10000Mb/s, Link detected: yes
+
+# Check driver loaded with allow_unsupported_sfp
+dmesg | grep -i "allow_unsupported_sfp"
+# Expected: ixgbe ...: allow_unsupported_sfp Enabled
+```
+
+## DKMS (Survive Kernel Upgrades)
+
+To automatically rebuild the driver when the kernel is upgraded:
+
+```bash
+DRIVER_VERSION=6.3.4
+cp -r /path/to/ethernet-linux-ixgbe /usr/src/ixgbe-${DRIVER_VERSION}
+
+cat > /usr/src/ixgbe-${DRIVER_VERSION}/dkms.conf << EOF
+PACKAGE_NAME="ixgbe"
+PACKAGE_VERSION="${DRIVER_VERSION}"
+BUILT_MODULE_NAME[0]="ixgbe"
+BUILT_MODULE_LOCATION[0]="src/"
+DEST_MODULE_LOCATION[0]="/updates/drivers/net/ethernet/intel/ixgbe/"
+MAKE[0]="cd src && make CFLAGS_EXTRA='-DDISABLE_PCI_AER'"
+CLEAN="cd src && make clean"
+AUTOINSTALL="yes"
+EOF
+
+dkms add -m ixgbe -v ${DRIVER_VERSION}
+dkms build -m ixgbe -v ${DRIVER_VERSION}
+dkms install -m ixgbe -v ${DRIVER_VERSION}
+```
+
+## Background
+
+This issue affects everyone using 10GBase-T (copper RJ45) SFP+ transceivers in Intel 82599-based NICs. Affected users include those with:
+
+- FS.com SFP-10GM-T-30 / SFP-10GM-T-80
+- 10Gtek 10GBase-T SFP+ modules
+- Various other copper SFP+ transceivers
+
+Related discussions:
+- [vfreex/ixgbe-fix gist](https://gist.github.com/vfreex/) — partial fix for vendor lock only
+- [DPDK Bug 263](https://bugs.dpdk.org/show_bug.cgi?id=263) — same root cause in DPDK
+- Proxmox forum threads about unsupported SFP+ modules
+
+## License
+
+This patch is provided under the same license as the original Intel ixgbe driver (GPL v2).

patches/0001-ixgbe-add-10GBase-T-SFP-support.patch

@@ -0,0 +1,23 @@
+diff --git a/src/ixgbe_phy.c b/src/ixgbe_phy.c
+index 7ffb817..4d91062 100644
+--- a/src/ixgbe_phy.c
++++ b/src/ixgbe_phy.c
+@@ -1314,6 +1314,18 @@ s32 ixgbe_identify_sfp_module_generic(struct ixgbe_hw *hw)
+ 		if (status != IXGBE_SUCCESS)
+ 			goto err_read_i2c_eeprom;
+
++		/* 10GBase-T SFP+ modules have no SFF-8472 compliance code
++		 * (the standard only defines bits for fiber: SR, LR, LRM, ER).
++		 * They report comp_codes_10g=0x00 and cable_tech=0x00, causing
++		 * the driver to reject them before allow_unsupported_sfp is
++		 * consulted. Force SR classification so the module is accepted
++		 * when allow_unsupported_sfp is explicitly enabled.
++		 */
++		if (comp_codes_10g == 0 && cable_tech == 0 &&
++		    hw->allow_unsupported_sfp) {
++			comp_codes_10g = IXGBE_SFF_10GBASESR_CAPABLE;
++		}
++
+ 		 /* ID Module
+ 		  * =========
+ 		  * 0   SFP_DA_CU

src/ixgbe_phy.c

@@ -1314,6 +1314,18 @@ s32 ixgbe_identify_sfp_module_generic(struct ixgbe_hw *hw)
 		if (status != IXGBE_SUCCESS)
 			goto err_read_i2c_eeprom;
 
+		/* 10GBase-T SFP+ modules have no SFF-8472 compliance code
+		 * (the standard only defines bits for fiber: SR, LR, LRM, ER).
+		 * They report comp_codes_10g=0x00 and cable_tech=0x00, causing
+		 * the driver to reject them before allow_unsupported_sfp is
+		 * consulted. Force SR classification so the module is accepted
+		 * when allow_unsupported_sfp is explicitly enabled.
+		 */
+		if (comp_codes_10g == 0 && cable_tech == 0 &&
+		    hw->allow_unsupported_sfp) {
+			comp_codes_10g = IXGBE_SFF_10GBASESR_CAPABLE;
+		}
+
 		 /* ID Module
 		  * =========
 		  * 0   SFP_DA_CU