[PATCH 3.7] mac80211: fix remain-on-channel (non-)cancelling

[PATCH 3.7] mac80211: fix remain-on-channel (non-)cancelling

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

Felix Liao reported that when an interface is set DOWN
while another interface is executing a ROC, the warning
in ieee80211_start_next_roc() (about the first item on
the list having started already) triggers.

This is because ieee80211_roc_purge() calls it even if
it never actually changed the list of ROC items. To fix
this, simply remove the function call. If it is needed
then it will be done by the ieee80211_sw_roc_work()
function when the ROC item that is being removed while
active is cleaned up.

Cc: stable@vger.kernel.org
Reported-by: Felix Liao <Felix.Liao@watchguard.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/offchannel.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 83608ac..2c84185 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -458,8 +458,6 @@ void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
 		list_move_tail(&roc->list, &tmp_list);
 		roc->abort = true;
 	}
-
-	ieee80211_start_next_roc(local);
 	mutex_unlock(&local->mtx);
 
 	list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
-- 
1.8.0

Re: [PATCH 3.7] mac80211: fix remain-on-channel (non-)cancelling

[Johannes Berg]

On Sat, 2012-11-24 at 00:32 +0100, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com>
> 
> Felix Liao reported that when an interface is set DOWN
> while another interface is executing a ROC, the warning
> in ieee80211_start_next_roc() (about the first item on
> the list having started already) triggers.
> 
> This is because ieee80211_roc_purge() calls it even if
> it never actually changed the list of ROC items. To fix
> this, simply remove the function call. If it is needed
> then it will be done by the ieee80211_sw_roc_work()
> function when the ROC item that is being removed while
> active is cleaned up.

I should mention that the only effect of the patch is removing the
warning, other than that the code behaves the same before and after the
patch.

johannes