This is partial revert and fix for commit
85f72bc839705294b32b6c16b491c0422f0a71b3 "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 85f72bc839705294b32b6c16b491c0422f0a71b3
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: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
---
net/mac80211/main.c | 3 +--
net/mac80211/pm.c | 3 +--
net/mac80211/scan.c | 35 +++++++++++++++++++++++++----------
3 files changed, 27 insertions(+), 14 deletions(-)
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 494dba1..8ba09ff 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -304,8 +304,7 @@ 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_scan_cancel(local);
ieee80211_reconfig(local);
rtnl_unlock();
}
diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index ce671df..d287fde 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -12,8 +12,7 @@ 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_scan_cancel(local);
ieee80211_stop_queues_by_reason(hw,
IEEE80211_QUEUE_STOP_REASON_SUSPEND);
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 5bb2254..d35003a 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -794,24 +794,39 @@ 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 (finish)
- __ieee80211_scan_completed_finish(&local->hw, false);
+ 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);
+ }
}
--
1.7.1
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