ath9k dropping connections

[Flávio Silveira <flavioguiraldo@xxxxxxxxx>]

Good evening,

  I have a wireless router running LEDE Reboot (SNAPSHOT, 
r5445-04127f0fec), with kernel 4.9.65 and I'm seeing connections being 
dropped without any error in dmesg. To fix I have to restart wifi by 
issuing "wifi down; wifi up"

  It was previously running OpenWrt Barrier Breaker and was presenting 
the same issue, except it would give me an error similar to this one: 
"ath: phy0: Failed to stop TX DMA, queues=0x005!"

  After doing some research it seems this error is related to 
environment interference and it was fixed in later kernel versions, the 
reason I gave LEDE a try. It makes sense, because this router worked 
wonderfully for at least a year before giving this issue.

  The reason I am sending this e-mail is to receive suggestions on how 
can I debug it properly, because, as pointed above, dmesg shows no errors.

Regards,
  Flavio Silveira