** Description changed: BugLink: https://bugs.launchpad.net/bugs/2164898 [ Impact ] We found a non-conformant behavior in USB4 Host Interface on some AMD APUs. This behavior may lead to system hang when communicate using transmit/receive rings to another USB4 router. Specifically, DMA path setup and teardown cycles may cause the Tx ring to hang. [ Fix ] Cherry-pick the following patch, which is currently in linux-next: 1. thunderbolt: Add quirk to reset host interface on DMA path teardown for AMD USB4 routers[1] [ Test ] 0. Prepare 2 systems with the said USB4 Host I/F 1. Boot the new kernel 2. Connect USB4 ports on them with a USB4 cable, and start host-to-host USB4 traffic between them through, say, iperf3. - 3. Unplug the cable while transmission is happening. Either of these 2 systems shouldn't hang. + 3. Unplug the cable while transmission is happening. None of the system should hang. [ Where problems could occur ] On disconnection of host-to-host communication (either USB4STREAM or netdev-based code path), this makes matched AMD USB4 host interface reset. [ Additional Information ] [1] https://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt.git/commit/?h=next&id=f1de1fc5f632cdeae1f5c2984572ab710d4dfcaa
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2164898 Title: [SRU] Add workaround for some non-conformant USB4 Host on some AMD platforms To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-oem-7.0/+bug/2164898/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
