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authorStanislaw Gruszka <sgruszka@redhat.com>2010-10-06 11:22:10 +0200
committerJohn W. Linville <linville@tuxdriver.com>2010-10-06 16:30:42 -0400
commit4136c4224ccf1907d309e1cdfaefef9da97dbc5e (patch)
treebe65af6057850d068b7858f5679a00b64fb2e92d /net/mac80211/scan.c
parente229f844d7223b7063bea1e649203ac521a58fe1 (diff)
downloadop-kernel-dev-4136c4224ccf1907d309e1cdfaefef9da97dbc5e.zip
op-kernel-dev-4136c4224ccf1907d309e1cdfaefef9da97dbc5e.tar.gz
mac80211: assure we also cancel deferred scan request
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@redhat.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/scan.c')
-rw-r--r--net/mac80211/scan.c35
1 files changed, 25 insertions, 10 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 6964a45..4dbef71 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -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 (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);
+ }
}
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