So instead of downgrading my BIOS, I've updated it from 1.2.29 to version 1.3.0 which was released two days ago by DELL for the XPS15 9550. USB ports at the TB16 is now working without issues again.
I don't get any checksum errors, too: for i in 1 2 3 4; do curl -s http://de.releases.ubuntu.com/zesty/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done 4672ce371fb3c1170a9e71bc4b2810b9 1.iso 4672ce371fb3c1170a9e71bc4b2810b9 2.iso 4672ce371fb3c1170a9e71bc4b2810b9 3.iso 4672ce371fb3c1170a9e71bc4b2810b9 4.iso -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1667750 Title: xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1667750/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs