From 242ab7ad689accafd5e87ffd22b85cf1bf7fbbef Mon Sep 17 00:00:00 2001 From: Bob Copeland Date: Mon, 21 Dec 2009 22:26:48 -0500 Subject: ath5k: fix SWI calibration interrupt storm The calibration period is now invoked by triggering a software interrupt from within the ISR by ath5k_hw_calibration_poll() instead of via a timer. However, the calibration interval isn't initialized before interrupts are enabled, so we can have a situation where an interrupt occurs before the interval is assigned, so the interval is actually negative. As a result, the ISR will arm a software interrupt to schedule the tasklet, and then rearm it when the SWI is processed, and so on, leading to a softlockup at modprobe time. Move the initialization order around so the calibration interval is set before interrupts are active. Another possible fix is to schedule the tasklet directly from the poll routine, but I think there are additional plans for the SWI. Signed-off-by: Bob Copeland Cc: stable@kernel.org Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath5k/base.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c index a4c086f069b..2a446a93824 100644 --- a/drivers/net/wireless/ath/ath5k/base.c +++ b/drivers/net/wireless/ath/ath5k/base.c @@ -2381,6 +2381,9 @@ ath5k_init(struct ath5k_softc *sc) */ ath5k_stop_locked(sc); + /* Set PHY calibration interval */ + ah->ah_cal_intval = ath5k_calinterval; + /* * The basic interface to setting the hardware in a good * state is ``reset''. On return the hardware is known to @@ -2408,10 +2411,6 @@ ath5k_init(struct ath5k_softc *sc) /* Set ack to be sent at low bit-rates */ ath5k_hw_set_ack_bitrate_high(ah, false); - - /* Set PHY calibration inteval */ - ah->ah_cal_intval = ath5k_calinterval; - ret = 0; done: mmiowb(); -- cgit v1.2.3