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iwlwifi: mvm: don't try to stop scans that are not running anymore 

In certain conditions, mac80211 may ask us to stop a scan (scheduled
or normal) that is not running anymore.  This can also happen when we
are doing a different type of scan, for instance, mac80211 can ask us
to stop a scheduled scan when we are running a normal scan, due to
some race conditions.  In this case, we would stop the wrong type of
scan and leave everything everything in a wrong state.

To fix this, simply ignore scan stop requests for scans types that are
not running.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
This commit is contained in:
Luciano Coelho 2015-02-06 10:19:05 +02:00 committed by Emmanuel Grumbach
parent 57bff14850
commit e7d3abab81
1 changed files with 31 additions and 2 deletions
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33
drivers/net/wireless/iwlwifi/mvm/mac80211.c
View File

@ -2215,7 +2215,19 @@ static void iwl_mvm_mac_cancel_hw_scan(struct ieee80211_hw *hw,
mutex_lock(&mvm->mutex);
iwl_mvm_cancel_scan(mvm);
/* Due to a race condition, it's possible that mac80211 asks
* us to stop a hw_scan when it's already stopped. This can
* happen, for instance, if we stopped the scan ourselves,
* called ieee80211_scan_completed() and the userspace called
* cancel scan scan before ieee80211_scan_work() could run.
* To handle that, simply return if the scan is not running.
*/
/* FIXME: for now, we ignore this race for UMAC scans, since
* they don't set the scan_status.
*/
if ((mvm->scan_status == IWL_MVM_SCAN_OS) ||
(mvm->fw->ucode_capa.capa[0] & IWL_UCODE_TLV_CAPA_UMAC_SCAN))
iwl_mvm_cancel_scan(mvm);
mutex_unlock(&mvm->mutex);
}
@ -2559,12 +2571,29 @@ static int iwl_mvm_mac_sched_scan_stop(struct ieee80211_hw *hw,
int ret;
mutex_lock(&mvm->mutex);
/* Due to a race condition, it's possible that mac80211 asks
* us to stop a sched_scan when it's already stopped. This
* can happen, for instance, if we stopped the scan ourselves,
* called ieee80211_sched_scan_stopped() and the userspace called
* stop sched scan scan before ieee80211_sched_scan_stopped_work()
* could run. To handle this, simply return if the scan is
* not running.
*/
/* FIXME: for now, we ignore this race for UMAC scans, since
* they don't set the scan_status.
*/
if (mvm->scan_status != IWL_MVM_SCAN_SCHED &&
!(mvm->fw->ucode_capa.capa[0] & IWL_UCODE_TLV_CAPA_UMAC_SCAN)) {
mutex_unlock(&mvm->mutex);
return 0;
}
ret = iwl_mvm_scan_offload_stop(mvm, false);
mutex_unlock(&mvm->mutex);
iwl_mvm_wait_for_async_handlers(mvm);
return ret;
}
static int iwl_mvm_mac_set_key(struct ieee80211_hw *hw,