From mboxrd@z Thu Jan  1 00:00:00 1970
From: Adrian Chadd <adrian@freebsd.org>
Date: Sat, 27 Aug 2016 21:44:39 -0700
Subject: [ath9k-devel] Interrupt issue on ARM with SMP
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Hi,

So, interrupt handling is finnicky. It's possible there's already a
posted interrupt waiting somewhere. Ideally you'd do a write-then-read
in each of the interrupt blocks between your device and the CPU to
ensure thing are synced. Otherwise the different frequencies in
different blocks in the ARM code mean you get interrupts after you've
cleared the interrupt itself, because it hasn't yet posted in that
particular hardware block.

Yay, etc.



-adrian