** Description changed: BugLink: https://bugs.launchpad.net/bugs/2143197 [Impact] Dell Thunderbolt dock ethernet (Intel I226 NIC) can fail to initialize after - hotplug. After unplug/replug, the interface may appear with an invalid MAC - (00:00:00:00:00:00) or stale MAC and wired networking does not work. + hotplug with MAC passthrough enabled. After unplug/replug, the interface may appear with an dock MAC address but not MAC passthrough address then cause stale MAC and wired networking does not work. Cold boot is unaffected; issue is hotplug-specific. Affected systems include Dell platforms with Thunderbolt docks such as - WD25TB4-class docks carrying Intel I226 ethernet. + SD25TB5-class docks carrying Intel I226 ethernet. [Fix] Increase the existing Thunderbolt MAC passthrough wait in igc probe path: - from 600ms - to 1000ms - Ubuntu already carries a SAUCE workaround (commit 534981aaa8) that uses + Ubuntu already carries a SAUCE workaround (commit 534981aaa831) that uses fixed delay timing. Newer Dell docks need a longer timing window. Debug testing shows BIOS MAC update timing: - cold boot: MAC already correct at probe start - hotplug: MAC becomes correct at ~300-800ms after probe starts Use 1000ms (observed 800ms worst-case + margin) to make hotplug reliable. Upstream context: https://lore.kernel.org/lkml/[email protected]/ (Upstream preferred polling over fixed delay; Ubuntu keeps minimal stable fixed-delay workaround.) [Test Plan] 1. Boot with dock attached; confirm interface has valid MAC and link works. 2. Unplug dock, wait 5s, replug, wait for enumeration. 3. Verify MAC is valid/correct and connectivity works. 4. Repeat hotplug cycle 10 times. Expected results: - Without this change: intermittent hotplug failures (~50-80% observed). - With this change: MAC is correct and networking works on every cycle. [Where problems could occur] - Probe time for Thunderbolt-attached igc devices increases by 400ms. - Scope is limited to pci_is_thunderbolt_attached() path. - If a future dock requires >1000ms, hotplug failure could still occur. - No functional changes beyond extending an existing sleep.
** Summary changed: - igc: Increase Thunderbolt MAC passthrough delay to 1000ms + UBUNTU: SAUCE: igc: Increase Thunderbolt MAC passthrough delay to 1000ms -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2143197 Title: UBUNTU: SAUCE: igc: Increase Thunderbolt MAC passthrough delay to 1000ms To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-oem-6.17/+bug/2143197/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
