Re: ath9k_htc - Division by zero in kernel (as well as firmware panic)

On Sat, Jun 3, 2017 at 2:57 AM, Oleksij Rempel [off-list ref] wrote:

Hm... this function and file:
linux/drivers/net/wireless/ath/ath9k/common-beacon.c
didn't changed since 2015. So, it should be some thing different.
Can you run
git bisect to find exact patch caused this regression?

That was the first time I experienced the x/0 issue and don't know how
I'd reproduce it.

Yes, this is "normal" problem. The firmware has no error handler for PCI
bus related exceptions. So if we filed to read PCI bus first time, we
have choice to Ooops and stall or Ooops and reboot ASAP. So we reboot
and provide an kernel "firmware panic!" message.
Every one who can or will to fix this, is welcome.

Thanks for that explanation. I'm not sure it's something I could
tackle though. My best bet in the meantime is to coax systemd to
restart the services when the device pops up. However, every attempt
has failed so far.

It is possible. If adapter is used in AP mode, then lots of WiFi noise
is dumped over this interface. I assume the reproducibility depends on
external environment, not internal.

I find this quite believable. I have 2.4ghz happening with the
TP-Link, ZTE Mobley, bluetooth, logitech unifying, usb 3.0. Though all
4 devices are going through the USB 2.0 port, and the tp-link and
mobley have long usb cables in the attic and the hub connects through
a 2m usb extension. So yeah, I've got a lot of variables in play.