Public bug reported: 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 22.04, therefore, this issue will also occur on 22.04.
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 22.04 version? ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2100827 Title: ubuntu-22.04: Root port link speed degradation to 2.5GT/s after nvme hot plug To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2100827/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs