Commit 4136c422 authored by Stanislaw Gruszka's avatar Stanislaw Gruszka Committed by John W. Linville
Browse files

mac80211: assure we also cancel deferred scan request 



This is partial revert and fix for commit
85f72bc8 "mac80211: only cancel
software-based scans on suspend"

When cfg80211 request the scan and mac80211 perform some management work,
we defer the scan request. We do not canceling such requests when calling
ieee80211_scan_cancel(), because of SCAN_SW_SCANNING bit check just
before the call. So fix that problem.

Another problem, which commit 85f72bc8
tries to solve, is we can not cancel HW scan. Hence patch make
ieee80211_scan_cancel() ignore HW scan (see code comments). Keeping
local->mtx lock assures that the deferred scan will not become
"working" HW scan.

Signed-off-by: default avatarStanislaw Gruszka <sgruszka@redhat.com>
Acked-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent e229f844

net/mac80211/main.c

+1 −2
Original line number Diff line number Diff line
@@ -307,7 +307,6 @@ static void ieee80211_restart_work(struct work_struct *work) 
	mutex_unlock(&local->mtx);



	rtnl_lock();

	if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning)))

	ieee80211_scan_cancel(local);

	ieee80211_reconfig(local);

	rtnl_unlock();

net/mac80211/pm.c

+1 −2
Original line number Diff line number Diff line
@@ -12,7 +12,6 @@ int __ieee80211_suspend(struct ieee80211_hw *hw) 
	struct ieee80211_sub_if_data *sdata;

	struct sta_info *sta;



	if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning)))

	ieee80211_scan_cancel(local);



	ieee80211_stop_queues_by_reason(hw,

net/mac80211/scan.c

+25 −10
Original line number Diff line number Diff line
@@ -793,24 +793,39 @@ int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 
	return ret;

}



/*

 * Only call this function when a scan can't be queued -- under RTNL.

 */

void ieee80211_scan_cancel(struct ieee80211_local *local)

{

	bool abortscan;

	bool finish = false;



	cancel_delayed_work_sync(&local->scan_work);

	bool abortscan, finish;



	/*

	 * Only call this function when a scan can't be

	 * queued -- mostly at suspend under RTNL.

	 * We are only canceling software scan, or deferred scan that was not

	 * yet really started (see __ieee80211_start_scan ).

	 *

	 * Regarding hardware scan:

	 * - we can not call  __ieee80211_scan_completed() as when

	 *   SCAN_HW_SCANNING bit is set this function change

	 *   local->hw_scan_req to operate on 5G band, what race with

	 *   driver which can use local->hw_scan_req

	 *

	 * - we can not cancel scan_work since driver can schedule it

	 *   by ieee80211_scan_completed(..., true) to finish scan

	 *

	 * Hence low lever driver is responsible for canceling HW scan.

	 */



	mutex_lock(&local->mtx);

	abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) ||

		    (!local->scanning && local->scan_req);

	abortscan = local->scan_req && !test_bit(SCAN_HW_SCANNING, &local->scanning);

	if (abortscan)

		finish = __ieee80211_scan_completed(&local->hw, true, false);

	mutex_unlock(&local->mtx);



	if (abortscan) {

		/* The scan is canceled, but stop work from being pending */

		cancel_delayed_work_sync(&local->scan_work);

		if (finish)

			__ieee80211_scan_completed_finish(&local->hw, false);

	}

}

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