FWIW, the C-states workaround from this post works for me and resolves the hot-plugging issue with TB16: https://www.dell.com/community/XPS/XPS-13-9300-and-WD19TB-linux-problem/m-p/7842208/highlight/true#M81522
Currently running BIOS 1.9.1, TBT firmware V65, TB16 firmware 1.0.5 and kernel 5.13.0-1012-oem.
I hope this helps pin down the bug or at least becomes useful for others who run into this.
FWIW, the C-states workaround from this post works for me and resolves the hot-plugging issue with TB16: https:/ /www.dell. com/community/ XPS/XPS- 13-9300- and-WD19TB- linux-problem/ m-p/7842208/ highlight/ true#M81522
Currently running BIOS 1.9.1, TBT firmware V65, TB16 firmware 1.0.5 and kernel 5.13.0-1012-oem.
I hope this helps pin down the bug or at least becomes useful for others who run into this.