mac80211: perform scan cancel in hw reset work

Move ieee80211_scan_cancel() and all other related code to
ieee80211_restart_work() as ieee80211_restart_hw() is intended to be
callable from any context.

Fix a bug that RTNL lock is not taken during ieee80211_cancel_scan().

Take local->mtx before WARN(test_bit(SCAN_HW_SCANNING, &local->scanning)
to prevent the race condition with __ieee80211_start_scan() described
here: http://marc.info/?l=linux-wireless&m=128516716810537&w=2

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Stanislaw Gruszka 2010-10-01 14:05:27 +02:00 committed by John W. Linville
parent 8e0167a4bd
commit bc86863de6
1 changed files with 10 additions and 9 deletions

View File

@ -295,7 +295,17 @@ static void ieee80211_restart_work(struct work_struct *work)
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, restart_work);
/* wait for scan work complete */
flush_workqueue(local->workqueue);
mutex_lock(&local->mtx);
WARN(test_bit(SCAN_HW_SCANNING, &local->scanning),
"%s called with hardware scan in progress\n", __func__);
mutex_unlock(&local->mtx);
rtnl_lock();
if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning)))
ieee80211_scan_cancel(local);
ieee80211_reconfig(local);
rtnl_unlock();
}
@ -306,15 +316,6 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw)
trace_api_restart_hw(local);
/* wait for scan work complete */
flush_workqueue(local->workqueue);
WARN(test_bit(SCAN_HW_SCANNING, &local->scanning),
"%s called with hardware scan in progress\n", __func__);
if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning)))
ieee80211_scan_cancel(local);
/* use this reason, ieee80211_reconfig will unblock it */
ieee80211_stop_queues_by_reason(hw,
IEEE80211_QUEUE_STOP_REASON_SUSPEND);