Control: tags -1 - moreinfo On Mon, Jun 29, 2026 at 12:51:27AM +0200, [email protected] wrote: > Sorry for the trouble, I was wrong. > > I incorrectly diagnosed this as a kernel regression introduced in 6.12.94, > problem is in the dock itself. > > The "failed to enable CL states" / "failed to enable TMU" / "PCIe tunnel > activation failed" messages were a SYMPTOM of the dock's internal > tunnel/routing state being stuck after repeated failed > re-attach attempts, not the root cause. The actual fix was the cold > power-cycle. > (An earlier workaround, thunderbolt.clx=0, appeared to help, but it was the > power-cycle and not the kernel parameter that restored function. clx=0 is not > required.) > > The kernel was upgraded 6.12.90-2 -> 6.12.94-1 via a package update. A new > kernel only takes effect on reboot, so the dock kept working until the next > reboot. The trigger was the reboot after > the kernel install, not the kernel code. > > The dock does not reliably re-attach across a warm reboot and needs a > coldpower-cycle to reset. > Also, I reverted to the kernel 6.12.90 and then back to 6.12.94 and it keeps > working in both directions. > (In normal day-to-day use this has occurred three times in a row following a > kernel update, yet when I deliberately try to reproduce it, the dock works > fine) > > Sorry again
Thanks a lot for reporting back. I'm leaning towards closing then this bugreport assuming it is solely an issue with the Dock. But I will wait until having discussed it with other members in the kernel team. Regards, Salvatore
