From: Liang Li Date: Thu, 2 Aug 2012 22:55:41 +0000 (-0400) Subject: cfg80211: fix interface combinations check for ADHOC(IBSS) X-Git-Tag: v3.2.27~64 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f0618dab274183ec2b8e0d0f3c2adafd994caf02;p=pandora-kernel.git cfg80211: fix interface combinations check for ADHOC(IBSS) 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 Signed-off-by: Paul Gortmaker Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed