[FS#241] ath9k strange behaviour since wireless-testing 2016-10-08

[LEDE Bugs]

The following task has a new comment added:

FS#241 - ath9k strange behaviour since wireless-testing 2016-10-08
User who did this - ckdalsdk12 (ckdalsdk12)

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My Archer C7 v2 has same issue.
There is also a packet loss problem with ath9k.(2.4GHz)
The problem occurs when I send a ping from the router to the client.

I reverted source code to r1831(8869dd) and built it. r1831 build has no issue.
I also guess wireless-testing 2016-10-08 commit(ad51e0) caused problems.
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=241#comment694