[FS#13] Ath9k AP stays up for connected clients but doesn't show in scan on new ones

[LEDE Bugs]

The following task has a new comment added:

FS#13 - Ath9k AP stays up for connected clients but doesn't show in scan on new ones
User who did this - IronicSven (IronicSven)

----------
Hi Felix,

I've spend some time today to understand tiny parts of the ath9k code and got better debugging results with this debugging level:

root at FlensNet:~# echo 0x00266665 > /sys/kernel/debug/ieee80211/phy0/ath9k/debug


It shows that there are recurring beacon problems before multiple calibrations and the tx hung:


...
Sat Dec 31 18:07:32 2016 kern.debug kernel: [ 1187.102795] ath: phy0: resume beacon xmit after 1 misses
Sat Dec 31 18:07:32 2016 kern.debug kernel: [ 1187.115571] ath: phy0: missed 1 consecutive beacons
...


The missing beacons might be the root cause.

You can find the complete syslog here: http://pastebin.com/8rcr3Gq1

PS: Building from your staging tree works now for me.
----------

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=13#comment1126