Panic with wifi + usb in latest FreeBSD-current

[Warner Losh]

I'm running current as of -2h ago.

When I plug in my rtwn0 device and it configures, etc, I get:

rtwn0 on uhub 0
rtwn0: <realtek 802.11n WLAN Adapter, class 0/0, rev 2.00/2.00, addr 4> on
usbus0
rtwn0: MAC/BB RTL8188CUS, RF 6052 1T1R
<date> host dpa_supplicant[1619]: ioctl[SIOS80211, op=20, val=0,
arg_len=7]: Invalid argument
panic: sleepq_add: td <hex> to sleep on wchan <hex> with sleeping prohibited
cpuid = 5
time = 1600057358
KDB: stack backtrace:
...
panic()
sleepq_add()
_cv_wait()
usbd_do_request_flags
rtwn_do_request
rtwn_usb_read_4
rtwn_rx_common
rtwn_bulk_rx_callback
usbd_callback_wrapper
usb_command_wrapper
usb_callback_proc
usb_process
...

I've done a fresh installworld and installkernel, but am running packages
from late may since I've not updated them. I've updated the iichid and
drm-kmod ports and rebuilt them and reinstalled them as well (so I know
they aren't out of date).

Has anybody else seen this?

Warner