ath9k: implement IO serialization

All 802.11n PCI devices (Cardbus, PCI, mini-PCI) require
serialization of IO when on non-uniprocessor systems. PCI
express devices not not require this.

This should fix our only last standing open ath9k kernel.org
bugzilla bug report:

http://bugzilla.kernel.org/show_bug.cgi?id=12110

A port is probably required to older kernels and I can work on
that.

Cc: stable@kernel.org
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index 0e80990d8e84..3c04044a60bd 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -1336,6 +1336,7 @@ static int ath_init(u16 devid, struct ath_softc *sc)
                 printk(KERN_ERR "Unable to create debugfs files\n");
 
         spin_lock_init(&sc->sc_resetlock);
+        spin_lock_init(&sc->sc_serial_rw);
         mutex_init(&sc->mutex);
         tasklet_init(&sc->intr_tq, ath9k_tasklet, (unsigned long)sc);
         tasklet_init(&sc->bcon_tasklet, ath9k_beacon_tasklet,