As of this afternoon the wifi on my Dell XPS 13 stopped working (running Debian sid with kernel 4.4.0-1-amd64).
lspci detects my wifi card, but
ifconfig -a shows only the loopback interface.
I tried plugging in a USB wifi dongle which I have used recently with this laptop, and this also does not get recognized as a network interface. Both during startup and immediately after plugging in a USB wifi dongle, the following message appears in
cfg80211: Unknown symbol wireless_nlevent_flush (err 0)
cfg80211 sounds like it would be used for configuring 802.11 (i.e. wifi) so I suspect this kernel module isn't getting loaded correctly. Indeed, if I try to
modprobe cfg80211 I receive the following error:
modprobe: ERROR: could not insert 'cfg80211':? Unknown symbol in module, or unknown parameter (see dmesg)
dmesg I see the same message as above.
"unknown symbol wireless_nlevent_flush" yields zero results, although googling for just
wireless_nlevent_flush seems to imply that it relates to
wext somehow. One page suggested that
rfkill must be loaded before
rfkill is already loaded. I would be very grateful for any advice.