Public bug reported: [SRU Justification]
[Impact] Some Dell laptops where booting with Thunderbolt/USB4 devices connected the BIOS leaves some of the PCIe devices unconfigured. The kernel message shows "No bus number available for hot-added bridge". The connected devices can't be found. [Fix] Current linux PCI distribute the "spare" resources between hotplug ports on hot-add but have not done that upon the initial scan. The patches make the initial root bus scan path to do the same. [Test] 1. Power on the machine with Thunderbolt/USB4 devices connected. 2. Check the kernel message to see if "No bus number available for hot-added bridge" shows up or not. 3. Check if the Thunderbolt/USB4 devices works or not. [Where problems could occur] The patches only apply the same procedures on initial root bus scan which was not done. If the BIOS configures the PCI correctly, everything is OK. It only takes effect for the BIOS w/ unconfigured PCIe devices. ** Affects: linux (Ubuntu) Importance: Undecided Status: Invalid ** Affects: linux-oem-5.17 (Ubuntu) Importance: Undecided Status: New ** Affects: linux-oem-6.0 (Ubuntu) Importance: Undecided Status: New ** Affects: linux (Ubuntu Jammy) Importance: Undecided Status: Invalid ** Affects: linux-oem-5.17 (Ubuntu Jammy) Importance: Undecided Status: New ** Affects: linux-oem-6.0 (Ubuntu Jammy) Importance: Undecided Status: New ** Affects: linux (Ubuntu Kinetic) Importance: Undecided Status: Invalid ** Affects: linux-oem-5.17 (Ubuntu Kinetic) Importance: Undecided Status: New ** Affects: linux-oem-6.0 (Ubuntu Kinetic) Importance: Undecided Status: New ** Also affects: linux-oem-5.17 (Ubuntu) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Jammy) Importance: Undecided Status: New ** Also affects: linux-oem-5.17 (Ubuntu Jammy) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Kinetic) Importance: Undecided Status: New ** Also affects: linux-oem-5.17 (Ubuntu Kinetic) Importance: Undecided Status: New ** Changed in: linux (Ubuntu Jammy) Status: New => Invalid ** Changed in: linux (Ubuntu Kinetic) Status: New => Invalid ** Also affects: linux-oem-6.0 (Ubuntu) Importance: Undecided Status: New -- 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/1991366 Title: Fix Thunderbolt device hotplug fail when connect via thunderbolt dock Status in linux package in Ubuntu: Invalid Status in linux-oem-5.17 package in Ubuntu: New Status in linux-oem-6.0 package in Ubuntu: New Status in linux source package in Jammy: Invalid Status in linux-oem-5.17 source package in Jammy: New Status in linux-oem-6.0 source package in Jammy: New Status in linux source package in Kinetic: Invalid Status in linux-oem-5.17 source package in Kinetic: New Status in linux-oem-6.0 source package in Kinetic: New Bug description: [SRU Justification] [Impact] Some Dell laptops where booting with Thunderbolt/USB4 devices connected the BIOS leaves some of the PCIe devices unconfigured. The kernel message shows "No bus number available for hot-added bridge". The connected devices can't be found. [Fix] Current linux PCI distribute the "spare" resources between hotplug ports on hot-add but have not done that upon the initial scan. The patches make the initial root bus scan path to do the same. [Test] 1. Power on the machine with Thunderbolt/USB4 devices connected. 2. Check the kernel message to see if "No bus number available for hot-added bridge" shows up or not. 3. Check if the Thunderbolt/USB4 devices works or not. [Where problems could occur] The patches only apply the same procedures on initial root bus scan which was not done. If the BIOS configures the PCI correctly, everything is OK. It only takes effect for the BIOS w/ unconfigured PCIe devices. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1991366/+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