Do a read-after-write to ensure the interrupt register update is flushed
authoradrian <adrian@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Sun, 27 Apr 2014 23:31:42 +0000 (23:31 +0000)
committeradrian <adrian@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Sun, 27 Apr 2014 23:31:42 +0000 (23:31 +0000)
commitef76c996ed32d87e8abb8d7a5bb629e443afe36c
tree27bdd0a02a57e6a744ae89f55b7dbfd343be5d36
parentc22a12d5d6d86759aaa5b8c82238cb8f8516d96a
Do a read-after-write to ensure the interrupt register update is flushed
to the hardware.

The QCA HAL has a comment noting that if this isn't done, modifications
to AR_IMR_S2 before AR_IMR is flushed may produce spurious interrupts.

Obtained from: QCA

git-svn-id: svn://svn.freebsd.org/base/head@265029 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
sys/dev/ath/ath_hal/ar5416/ar5416_interrupts.c