Comment 0 for bug 1668105

So we know this xhci_kcd was always shit in that it turns off the console usb keyboard for long running computers and that it on abrupt termination of Linux puts usb in a 12x slower mode. It is buggy, it was always buggy, and its getting worse.

With Linux 4.8.0-37, this crappy software decides to halt the host controller on boot, ie. turn off the console keyboard preventing any boot. I cannot think of any situation where anyone would want their host controller halted.

This is MacBook Pro 2015. So, it's already broken in UEFI-grub as it always was, ie. every key press takes 8 seconds, but you only need two, so you can boot in 16 s.

I tried to disable the xhci_kcd crap by using kernel parameter noxhci_port_switch or modprobe.blacklist=xhci_hcd neither which works.

Because it has crap in UEFI, the computer will not boot any external hard drive or usb fob. The only thing that works is Apple rescue that gets rid of the xhci garbage, and the boot os x immediately after that.

So the log output
xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
xhci_hcd 0000:00:14.0: xHCI host not responding to stop endpoint command.
- and a bit later:
xhci_hcd 0000:00:14.0: Assuming host is dying, halting host.
xhci_hcd 0000:00:14.0: HC died; cleaning up

This clown programming of Linux has to stop. Why would anyone ever want their host controller halted?