ath9k: skip ATH9K_INT_TIM_TIMER when we are idle

We should not be idle when we get the ATH9K_INT_TIM_TIMER,
otherwise its a sign of something broken in our design with
our idle state machine and mac80211. Skip these and WARN once
just in case this is triggerable.

Cc: Paul Stewart <pstew@google.com>
Cc: Amod Bodas <amod.bodas@atheros.com>
signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/main.c

@@ -765,6 +765,8 @@ irqreturn_t ath_isr(int irq, void *dev)
 
 	if (!(ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP))
 		if (status & ATH9K_INT_TIM_TIMER) {
+			if (ATH_DBG_WARN_ON_ONCE(sc->ps_idle))
+				goto chip_reset;
 			/* Clear RxAbort bit so that we can
 			 * receive frames */
 			ath9k_setpower(sc, ATH9K_PM_AWAKE);