mac80211: check interface is down before type change
authorJohannes Berg <johannes@sipsolutions.net>
Sun, 1 Nov 2009 18:25:40 +0000 (19:25 +0100)
committerJohn W. Linville <linville@tuxdriver.com>
Mon, 2 Nov 2009 20:14:07 +0000 (15:14 -0500)
commitc1f9a764cf47686b1f5a0cf87ada68d90056136a
tree77bff7f1361deb11e1b3c60470d9d5784c00a771
parent7400f42e9d765fa0656b432f3ab1245f9710f190
mac80211: check interface is down before type change

For some strange reason the netif_running() check
ended up after the actual type change instead of
before, potentially causing all kinds of problems
if the interface is up while changing the type;
one of the problems manifests itself as a warning:

WARNING: at net/mac80211/iface.c:651 ieee80211_teardown_sdata+0xda/0x1a0 [mac80211]()
Hardware name: Aspire one
Pid: 2596, comm: wpa_supplicant Tainted: G        W  2.6.31-10-generic #32-Ubuntu
Call Trace:
 [] warn_slowpath_common+0x6d/0xa0
 [] warn_slowpath_null+0x15/0x20
 [] ieee80211_teardown_sdata+0xda/0x1a0 [mac80211]
 [] ieee80211_if_change_type+0x4a/0xc0 [mac80211]
 [] ieee80211_change_iface+0x61/0xa0 [mac80211]
 [] cfg80211_wext_siwmode+0xc7/0x120 [cfg80211]
 [] ioctl_standard_call+0x58/0xf0

(http://www.kerneloops.org/searchweek.php?search=ieee80211_teardown_sdata)

Cc: Arjan van de Ven <arjan@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
net/mac80211/cfg.c