Avery Pennarun wrote:

Since around the beginning of time, ath9k aggregates have timed out after
5000 TU (around 5000ms) of inactivity, but nobody seems to be quite sure
why, and this magic number seems to have migrated around from one place to
another.  An openbsd mailing list recently had a patch to disable the
timeout completely, which they say matches some commercial routers:
https://www.mail-archive.com/tech@openbsd.org/msg29456.html

We actually did this for ath9k:
https://git.kernel.org/cgit/linux/kernel/git/wireless/wireless-testing.git/commit/?id=bd2ce6e43f65127bc723e7fcc044758cf8113260

Almost all APs set the timeout to zero, only mac80211 differs
and uses 5000 TUs. I guess ath9k lost this fix when the old
RC was removed and switched to minstrel.

Sujith