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mac80211: fix scan locking wrt. hw scan

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Releasing the scan mutex while starting scans
can lead to unexpected things happening, so
we shouldn't do that. Fix that and hold the
mutex across the scan triggering.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2010-07-30 13:30:47 +02:00 committed by John W. Linville
parent 02f5ba5bac
commit 1601b1e56e
1 changed files with 0 additions and 14 deletions
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14
net/mac80211/scan.c
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@ -400,19 +400,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
else
__set_bit(SCAN_SW_SCANNING, &local->scanning);
/*
* Kicking off the scan need not be protected,
* only the scan variable stuff, since now
* local->scan_req is assigned and other callers
* will abort their scan attempts.
*
* This avoids too many locking dependencies
* so that the scan completed calls have more
* locking freedom.
*/
ieee80211_recalc_idle(local);
mutex_unlock(&local->scan_mtx);
if (local->ops->hw_scan) {
WARN_ON(!ieee80211_prep_hw_scan(local));
@ -420,8 +408,6 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
} else
rc = ieee80211_start_sw_scan(local);
mutex_lock(&local->scan_mtx);
if (rc) {
kfree(local->hw_scan_req);
local->hw_scan_req = NULL;