NVIDIA ConnectX-8 SuperNIC Firmware Release Notes v40.48.1000 (February 2026 GA Release)

Bug Fixes in this Firmware Version

Internal Ref.

Issue

4823907 / NVbug 5742181

Description: Fixed an issue where, in certain configurations with the ConnectX-8 PCIe switch enabled, downstream devices (including GPUs) might not be detected and could drop from the PCI bus, with GPU sensors/properties reporting nan. This was caused by the device not receiving the required PERST# assertion during initialization, and was seen only when PCIe settings were manually modified via mlxconfig (e.g., restricting link speed/width or ASPM on specific PCI buses).

Note: On legacy firmware, additional configuration steps may still be required, as detailed below.

If you cannot update the firmware immediately, you can restore device detection using one of the following options:

  • Option 1: Reset configuration

    • Reset the device configuration to defaults:

      Copy
      Copied!
                  

      mlxconfig -d <device> -y reset

  • Option 2: Manual PERST configuration (B300)

    • Manually configure the PERST parameters:

      Copy
      Copied!
                  

      mlxconfig -d <device> set PCI_BUS10_CONTROL_EN=1 mlxconfig -d <device> set PCI_BUS10_PERST_SOURCE=2 mlxconfig -d <device> set PCI_BUS10_PERST_GPIO=8

Keywords: ConnectX-8 PCIe, GPU, PERST# assertion

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4786813

Description: Fixed an issue where the DPA kernel used unsafe ICM access during process creation/modification, which could cause the DPA kernel to hang during FLR.

Keywords: DPA kernel, FLR

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4884739

Description: Link failures may occasionally be observed at PAM4 speeds over optical interfaces in rare cases.

Keywords: PAM4 speeds, optical interfaces

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4804664 / 4806969

Description: Fixed an issue in the User Debugger “query caps” where it returned only the number of capabilities, not the capability bitmap.

Keywords: User Debugger “query caps”

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4813862 / 4146077

Description: Fixed an issue where CR dumps could time out when accessing xpl_top addresses across all three pcores.

Keywords: CR dump

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4833440

Description: Fixed an issue where the Virtio and NVMe EMU_MNG settings were exposed incorrectly, which could cause confusion when using mlxconfig.

Keywords: Virtio and NVMe emulation, mlxconfig

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4756451

Description: Fixed an issue where the PHY LED could show green during the initializing state when active speed was set to full speed. In IB mode, the initializing-state LED should be amber only.

Keywords: PHY LED

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4768546

Description: Fixed an issue where, on multi-PF-per-port systems, a PF FLR could impact the traffic bandwidth of other PFs on the same port.

Keywords: PF FLR

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4705918

Description: Fixed an issue where PTP could converge to an incorrect time/offset and report an inaccurate path delay.

Keywords: PTP

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4657792 / NVbug 5567725

Description: Fixed an issue where, in Flit Mode, the device could become unresponsive when receiving malformed or invalid traffic from a link partner.

Keywords: Flit Mode

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4484662

Description: Fixed an issue where mlxlink reported 0 values for SNR (media and host) due to incorrect local port mapping in firmware and an incorrect page number used by MFT.

Keywords: mlxlink

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4621747 / 4792742 / 4794290 / NVbug 5502241

Description: Fixed an issue where parallel accesses to the MCIA register could return incorrect data. In some hosts running ethtool -m <interface> repeatedly (e.g., once per second), this could intermittently report Identifier: 0x00 (unknown/no module), causing health checks to fail.

Keywords: MCIA register

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4686284 / NVbug 5607036

Description: Implemented IB extended port telemetry counters via the NSM Type 1 Get Port Telemetry Counters command, adding counters 19 and 20: NSM_LINK_ERROR_RECOVERY_COUNTER_CNTR_ID and NSM_LINK_DOWNED_COUNTER_CNTR_ID.

Keywords: IB extended port telemetry counters, NSM

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4758174 / NVbug 5698200

Description: Fixed a rare attestation certificate signature formatting issue by removing an unnecessary leading zero byte in the “r” or “s” value.

Keywords: Attestation certificate signature format

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4532684 / 4635872 / 4794865 / 4794866 / 4794867 / NVbug 5385446

Description: Fixed an issue by improving the ADP-RETX algorithm to avoid re-arming without performing a retransmission.

Keywords: ADP-RETX algorithm

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4542516 / 4554220

Description: Fixed an issue where, in certain Gen6 setups, RDMA READ bidirectional traffic required at least 5 QPs to reach full wire speed.

Keywords: RDMA READ bidirectional traffic

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4554763 / 4808657

Description: Fixed an issue affecting single-process, unidirectional RDMA READ to GPU memory (4 QPs, 128KB messages) by enabling ZERO_TOUCH_TUNING_ENABLE via MLXCONFIG.

Keywords: Zero Touch Tuning, mlxconfig

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4608214

Description: Fixed an issue where probe packets might not be sent under heavy traffic.

Keywords: PCC, ZTR_RTTCC, probe

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4450570 / 4780432 / 4780433

Description: Fixed an issue where the root complex sent MCTP-over-PCI messages before a BDF was assigned, causing responses to be sent with BDF 0. The fix ensures that MCTP messages routed by ID are ignored until a valid BDF is assigned.

Keywords: MCTP-over-PCI, BDF, MCTP messages

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4809134 / 4824635

Description: Fixed an issue where the steering tables were not updated after enabling partial Spectrum-X capabilities (BTH.AR) via LLPD.

Keywords: Steering tables, LLDP

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

4797308 / NVbug 5706024

Description: Fixed an issue where an intX message was sent with a Requester ID of 0, causing an ACS violation at the root port. The fix uses the correct BDF as the Requester ID instead of 0.

Keywords: intX message

Detected in version: 40.47.1026

Fixed in Release: 40.48.1000

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