Hi On Mon, Nov 06, 2017 at 04:57:09PM +0100, Richard Genoud wrote: > I get a soft lock-up while unbinding the USB driver on a TP-Link TL-WN727Nv3 (chipset 5370): > > # echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind > watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/u2:3:308] ... > I can trigger this each time. I can not reproduce this on my system (I'm using 4.14.0-rc6, but I don't think it's an issue). I think the problem may be caused by usb host controler driver, which can be different on your system. Does ftrace work on your platform ? If so could you use ftrace to provide rt2x00 functions trace when the probllem happen ? 3 short articles how to configure and use ftrace are here: https://lwn.net/Articles/365835/ https://lwn.net/Articles/366796/ https://lwn.net/Articles/370423/ Thanks Stanislaw
