Hi Tim， Our test engineer use ubuntu 24.04 reproduce this issue. They do hot repmove and hot plug on nvme device. And you can see, the nvme 7 downgrade to 2.5GT/s while nvme 6 is normal pcie link, they are the same type of nvme device. kern :info : [ 288.320053] pcieport 0000:86:02.0: pciehp: Slot(30): Card present kern :info : [ 289.115131] pci 0000:87:00.0: [1344:51c3] type 00 class 0x010802 PCIe Endpoint kern :info : [ 289.115176] pci 0000:87:00.0: BAR 0 [mem 0x00000000-0x0003ffff 64bit] kern :info : [ 289.115226] pci 0000:87:00.0: ROM [mem 0x00000000-0x0003ffff pref] kern :info : [ 289.115241] pci 0000:87:00.0: Max Payload Size set to 512 (was 128, max 512) kern :info : [ 289.115375] pci 0000:87:00.0: PME# supported from D0 D1 D3hot kern :info : [ 289.115816] pci 0000:87:00.0: Adding to iommu group 40 kern :info : [ 289.118666] pcieport 0000:86:02.0: ASPM: current common clock configuration is inconsistent, reconfiguring kern :info : [ 289.124069] pcieport 0000:86:02.0: bridge window [io 0x1000-0x0fff] to [bus 87] add_size 1000 kern :info : [ 289.124085] pcieport 0000:86:02.0: bridge window [io size 0x1000]: can't assign; no space kern :info : [ 289.124089] pcieport 0000:86:02.0: bridge window [io size 0x1000]: failed to assign kern :info : [ 289.124092] pcieport 0000:86:02.0: bridge window [io size 0x1000]: can't assign; no space kern :info : [ 289.124095] pcieport 0000:86:02.0: bridge window [io size 0x1000]: failed to assign kern :info : [ 289.124099] pci 0000:87:00.0: BAR 0 [mem 0xd4600000-0xd463ffff 64bit]: assigned kern :info : [ 289.124112] pci 0000:87:00.0: ROM [mem 0xd4640000-0xd467ffff pref]: assigned kern :info : [ 289.124115] pcieport 0000:86:02.0: PCI bridge to [bus 87] kern :info : [ 289.124121] pcieport 0000:86:02.0: bridge window [mem 0xd4600000-0xd46fffff] kern :info : [ 289.124125] pcieport 0000:86:02.0: bridge window [mem 0x1e6000000000-0x1e60001fffff 64bit pref] kern :info : [ 289.124694] nvme nvme6: pci function 0000:87:00.0 kern :info : [ 289.124713] nvme 0000:87:00.0: enabling device (0000 -> 0002) kern :info : [ 293.734427] nvme nvme6: 255/0/0 default/read/poll queues
kern :info : [ 296.227642] pcieport 0000:86:04.0: pciehp: Slot(31): Card present kern :info : [ 296.355148] pci 0000:88:00.0: [1344:51c3] type 00 class 0x010802 PCIe Endpoint kern :info : [ 296.355199] pci 0000:88:00.0: BAR 0 [mem 0x00000000-0x0003ffff 64bit] kern :info : [ 296.355257] pci 0000:88:00.0: ROM [mem 0x00000000-0x0003ffff pref] kern :info : [ 296.355275] pci 0000:88:00.0: Max Payload Size set to 512 (was 128, max 512) kern :info : [ 296.355438] pci 0000:88:00.0: PME# supported from D0 D1 D3hot kern :info : [ 296.355543] pci 0000:88:00.0: 8.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x4 link at 0000:86:04.0 (capable of 63.012 Gb/s with 16.0 GT/s PCIe x4 link) kern :info : [ 296.355977] pci 0000:88:00.0: Adding to iommu group 41 kern :info : [ 296.359042] pcieport 0000:86:04.0: ASPM: current common clock configuration is inconsistent, reconfiguring kern :info : [ 296.362046] pcieport 0000:86:04.0: bridge window [io 0x1000-0x0fff] to [bus 88] add_size 1000 kern :info : [ 296.362072] pcieport 0000:86:04.0: bridge window [io size 0x1000]: can't assign; no space kern :info : [ 296.362079] pcieport 0000:86:04.0: bridge window [io size 0x1000]: failed to assign kern :info : [ 296.362086] pcieport 0000:86:04.0: bridge window [io size 0x1000]: can't assign; no space kern :info : [ 296.362090] pcieport 0000:86:04.0: bridge window [io size 0x1000]: failed to assign kern :info : [ 296.362097] pci 0000:88:00.0: BAR 0 [mem 0xd4500000-0xd453ffff 64bit]: assigned kern :info : [ 296.362119] pci 0000:88:00.0: ROM [mem 0xd4540000-0xd457ffff pref]: assigned kern :info : [ 296.362125] pcieport 0000:86:04.0: PCI bridge to [bus 88] kern :info : [ 296.362133] pcieport 0000:86:04.0: bridge window [mem 0xd4500000-0xd45fffff] kern :info : [ 296.362140] pcieport 0000:86:04.0: bridge window [mem 0x1e6000200000-0x1e60003fffff 64bit pref] kern :info : [ 296.362653] nvme nvme7: pci function 0000:88:00.0 kern :info : [ 296.362672] nvme 0000:88:00.0: enabling device (0000 -> 0002) kern :info : [ 301.227714] nvme nvme7: 255/0/0 default/read/poll queues -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2100828 Title: ubuntu-24.04: Root port link speed degradation to 2.5GT/s after nvme hot plug Status in linux package in Ubuntu: New Bug description: We found a kenrel issue on Redhat 9.4 and 9.5. nvme pcie link speed will downgrade to 2.5GT/s after hotplug. After analysis, we found this patch casued this issue: a89c82249c37 ("PCI: Work around PCIe link training failures"). This patch also merged into ubuntu 24.04, therefore, this issue will also occur on 24.04. The following commits fix this issue: commit de9a6c8d5dbfedb5eb3722c822da0490f6a59a45 PCI/bwctrl: Add pcie_set_target_speed() to set PCIe Link Speed f68dea13405c94381d08f42dbf0416261622bdad ("PCI: Revert to the original speed after PCIe failed link") Could you help check whetehr ubuntu need add the fix patch on 24.04 version? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2100828/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
