I was teted right now, the problem occurs also on stock kernel. # uname -a Linux m5c43 4.4.0-116-generic #140-Ubuntu SMP Mon Feb 12 21:23:04 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux Seems bug connected only with specific hardware, I'll provide more information about this. I uses HP Moonshot x710x xartridge: # lspci 00:00.0 Host bridge: Intel Corporation Sky Lake Host Bridge/DRAM Registers (rev 0a) 00:01.0 PCI bridge: Intel Corporation Sky Lake PCIe Controller (x16) (rev 0a) 00:02.0 VGA compatible controller: Intel Corporation Device 193a (rev 09) 00:14.0 USB controller: Intel Corporation Sunrise Point-H USB 3.0 xHCI Controller (rev 31) 00:16.0 Communication controller: Intel Corporation Sunrise Point-H CSME HECI #1 (rev 31) 00:17.0 SATA controller: Intel Corporation Sunrise Point-H SATA controller [AHCI mode] (rev 31) 00:1b.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Root Port #17 (rev f1) 00:1c.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #1 (rev f1) 00:1c.3 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #4 (rev f1) 00:1c.4 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #5 (rev f1) 00:1d.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #9 (rev f1) 00:1d.5 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #14 (rev f1) 00:1f.0 ISA bridge: Intel Corporation Sunrise Point-H LPC Controller (rev 31) 00:1f.2 Memory controller: Intel Corporation Sunrise Point-H PMC (rev 31) 00:1f.4 SMBus: Intel Corporation Sunrise Point-H SMBus (rev 31) 01:00.0 System peripheral: Hewlett-Packard Company Integrated Lights-Out Standard Slave Instrumentation & System Support (rev 06) 01:00.1 VGA compatible controller: Matrox Electronics Systems Ltd. MGA G200EH (rev 01) 01:00.2 System peripheral: Hewlett-Packard Company Integrated Lights-Out Standard Management Processor Support and Messaging (rev 06) 01:00.4 USB controller: Hewlett-Packard Company Integrated Lights-Out Standard Virtual USB Controller (rev 03) 0e:00.0 Non-Volatile memory controller: Intel Corporation Device f1a5 (rev 03) 11:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro] 11:00.1 Ethernet controller: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function] # ethtool -i eno1 driver: mlx4_en version: 4.3-1.0.1 firmware-version: 2.40.5540 expansion-rom-version: bus-info: 0000:11:00.0 supports-statistics: yes supports-test: yes supports-eeprom-access: no supports-register-dump: no supports-priv-flags: yes # mst status MST modules: ------------ MST PCI module loaded MST PCI configuration module loaded MST devices: ------------ /dev/mst/mt4103_pci_cr0 - PCI direct access. domain:bus:dev.fn=0000:11:00.0 bar=0x7f100000 size=0x100000 Chip revision is: 00 /dev/mst/mt4103_pciconf0 - PCI configuration cycles access. domain:bus:dev.fn=0000:11:00.0 addr.reg=88 data.reg=92 Chip revision is: 00 # ibv_devinfo hca_id: mlx4_1 transport: InfiniBand (0) fw_ver: 2.40.5540 node_guid: 0014:0500:d300:bc52 sys_image_guid: f403:4303:00fd:102d vendor_id: 0x02c9 vendor_part_id: 4100 hw_ver: 0x0 board_id: HP_1690110017 phys_port_cnt: 2 Device ports: port: 1 state: PORT_DOWN (1) max_mtu: 4096 (5) active_mtu: 1024 (3) sm_lid: 0 port_lid: 0 port_lmc: 0x00 link_layer: Ethernet port: 2 state: PORT_DOWN (1) max_mtu: 4096 (5) active_mtu: 1024 (3) sm_lid: 0 port_lid: 0 port_lmc: 0x00 link_layer: Ethernet hca_id: mlx4_0 transport: InfiniBand (0) fw_ver: 2.40.5540 node_guid: f403:4303:00fd:102d sys_image_guid: f403:4303:00fd:102d vendor_id: 0x02c9 vendor_part_id: 4103 hw_ver: 0x0 board_id: HP_1690110017 phys_port_cnt: 2 Device ports: port: 1 state: PORT_ACTIVE (4) max_mtu: 4096 (5) active_mtu: 1024 (3) sm_lid: 0 port_lid: 0 port_lmc: 0x00 link_layer: Ethernet port: 2 state: PORT_ACTIVE (4) max_mtu: 4096 (5) active_mtu: 1024 (3) sm_lid: 0 port_lid: 0 port_lmc: 0x00 link_layer: Ethernet