2017-11-07 9:53 GMT+01:00 Stanislaw Gruszka <sgruszka@xxxxxxxxxx>: > Hi 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/ > I tried with ftrace, but I don't think there's a way to dump the trace when there's a soft lock-up (I can't do anything after the unbind, even the heartbeat led stopped blinking). I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but there's no /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :) Or I missed something in ftrace ? Thanks ! Richard. > Thanks > Stanislaw
