SWBA errors and no ssid

[Michal Kazior]

On 3 February 2016 at 20:33, Ann Lo <annlo.tech at gmail.com> wrote:
> Hello,
>
> We are seeking for expert opinions on "SWBA errors" and any possible
> workarounds. If we run AP+client mode, and the client scans for an
> nonexistent ssid, then "SWBA errors" happen easily. From this point
> on, the ssid of the AP is no longer visible. We use kernel 3.14.28,
> Qualcomm firmware 10.1.167.3-1, and WLE900VX. Qualcomm firmware
> 999.999.0.636 has the same problem except that it does not report
> "SWBA errors". Is it possible that we can fix this problem by porting
> some patches?
>
> Details of errors
> ============
> [ 3455.101199] ath10k: SWBA overrun on vdev 0
> [ 3455.203616] ath10k: SWBA overrun on vdev 0
> [ 3455.305992] ath10k: SWBA overrun on vdev 0
> [ 3455.408389] ath10k: SWBA overrun on vdev 0
> [ 3455.510768] ath10k: SWBA overrun on vdev 0
> [ 3455.613164] ath10k: SWBA overrun on vdev 0
> [ 3455.715557] ath10k: SWBA overrun on vdev 0
> [ 3455.817992] ath10k: SWBA overrun on vdev 0
> [ 3455.920360] ath10k: SWBA overrun on vdev 0
> [ 3456.022768] ath10k: SWBA overrun on vdev 0
> [ 3457.946735] uap0: failed to remove key (0, a4:2b:8c:04:6d:a8) from
> hardware (-11)
> [ 3460.118597] net_ratelimit: 40 callbacks suppressed
> [ 3460.123463] ath10k: SWBA overrun on vdev 0
> [ 3460.221003] ath10k: SWBA overrun on vdev 0
> [ 3460.323398] ath10k: SWBA overrun on vdev 0
> [ 3460.425785] ath10k: SWBA overrun on vdev 0
> [ 3460.528186] ath10k: SWBA overrun on vdev 0
> [ 3460.630568] ath10k: SWBA overrun on vdev 0
> [ 3460.732971] ath10k: SWBA overrun on vdev 0
> [ 3460.835370] ath10k: SWBA overrun on vdev 0
> [ 3460.937767] ath10k: SWBA overrun on vdev 0
> [ 3460.946679] ath10k: could not remove peer wep key 0 (-11)

Looks like firmware has hanged. I recall there were weird issues a
long time ago.

SWBA is an event reported by firmware to host prompting it to submit a
new beacon frame that is to be sent out. The "overrun" means that the
driver is unable to submit the beacon because firmware command pipe is
busy.

You're using quite an old kernel. Can you perhaps try 4.4? If you
can't replace the kernel for some reason did you think about using
backports[1]?

[1]: https://wireless.wiki.kernel.org/en/users/drivers/ath10k/backports


Michał