** Description changed: BugLink: https://bugs.launchpad.net/bugs/2141283 [ Impact ] On certain Lenovo platform, it has been observed that there's a chance that nvme hotplug through USB4 port isn't working properly. When hotplug doesn't work, PCIe packet trace shows that for some reasons BAR in the NVME was cleared. We've found that this issues doesn't seem reproducible on RC releases of v6.19 kernels. After a bisect, we've found that the following commits fix this symptom. [ Fix ] Cherry-pick the following commit in mainline into 6.17-oem: 1. a2f1e22390ac ("PCI/ERR: Ensure error recoverability at all times") 2. 383d89699c50 ("treewide: Drop pci_save_state() after pci_restore_state()") They also have been queued to 6.18-based stable tree. See [2] [ Test ] 1. Test thunderbolt storage hot plug on the said platform. The storage should function normally. - 2. Do sanity test on some devices that the second patch may impact. Make sure they enumerate. + 2. Do sanity test on OEM platforms with devices that the second patch may impact. [ Where problems could occur] The first patch ensures that there's at least a PCIe state snapshot available since driver model device add, so that the state_saved check in pci_restore_state() can be relaxed. Thus the second commit can drop those pci_save_state(). This changes PCIe register save/restore logic. Commit 2cbe3e361004 (UBUNTU: SAUCE: thunderbolt: Fix PCIe device enumeration with delayed rescan) in the OEM kernel may shield the said PCIe hotplug issues away. [ Additional information ] The said Lenovo platform seems to be on 6.14-oem kernel. In the event of kernel transition: - 6.17-oem: covered by this SRU. - 6.17-generic: These 2 commit are also queued in the 6.18-based stable tree. See [1]. - If there's plan getting those upstream stable patches to 6.17-based generic kernels, they will have it in the upcoming SRU cycles. + If there's plan getting those upstream stable patches to 6.17-based generic kernels, they will have it in the upcoming SRU cycles. - Other 6.20 kernels (e.g. resolute): these 2 commits are in 6.19. Resolute will have it. [1] https://lore.kernel.org/all/2026020755-stuck-rinse-89ff@gregkh/
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2141283 Title: [SRU] Fix USB4 hotplug on certain Lenovo Platforms To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-oem-6.17/+bug/2141283/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
