Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 59/65] cfg80211: fix interface combinations check for ADHOC(IBSS) | Date | Mon, 13 Aug 2012 15:14:43 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.4-stable review patch. If anyone has any objections, please let me know.
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From: Liang Li <liang.li@windriver.com>
partial of commit 8e8b41f9d8c8e63fc92f899ace8da91a490ac573 upstream.
As part of commit 463454b5dbd8 ("cfg80211: fix interface combinations check"), this extra check was introduced:
if ((all_iftypes & used_iftypes) != used_iftypes) goto cont;
However, most wireless NIC drivers did not advertise ADHOC in wiphy.iface_combinations[i].limits[] and hence we'll get -EBUSY when we bring up a ADHOC wlan with commands similar to:
# iwconfig wlan0 mode ad-hoc && ifconfig wlan0 up
In commit 8e8b41f9d8c8e ("cfg80211: enforce lack of interface combinations"), the change below fixes the issue:
if (total == 1) return 0;
But it also introduces other dependencies for stable. For example, a full cherry pick of 8e8b41f9d8c8e would introduce additional regressions unless we also start cherry picking driver specific fixes like the following:
9b4760e ath5k: add possible wiphy interface combinations 1ae2fc2 mac80211_hwsim: advertise interface combinations 20c8e8d ath9k: add possible wiphy interface combinations
And the purpose of the 'if (total == 1)' is to cover the specific use case (IBSS, adhoc) that was mentioned above. So we just pick the specific part out from 8e8b41f9d8c8e here.
Doing so gives stable kernels a way to fix the change introduced by 463454b5dbd8, without having to make cherry picks specific to various NIC drivers.
Signed-off-by: Liang Li <liang.li@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/wireless/util.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -974,6 +974,9 @@ int cfg80211_can_change_interface(struct } mutex_unlock(&rdev->devlist_mtx); + if (total == 1) + return 0; + for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) { const struct ieee80211_iface_combination *c; struct ieee80211_iface_limit *limits;
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