diff options
| -rw-r--r-- | net/wireless/core.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/net/wireless/core.c b/net/wireless/core.c index 24a21add..7eabd55 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -91,7 +91,6 @@ int wiphy_register(struct wiphy *wiphy) mutex_lock(&cfg80211_drv_mutex); - res = device_add(&drv->wiphy.dev); if (res) goto out_unlock; @@ -114,14 +113,26 @@ void wiphy_unregister(struct wiphy *wiphy) { struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); + /* protect the device list */ mutex_lock(&cfg80211_drv_mutex); - /* hold registered driver mutex during list removal as well - * to make sure no commands are in progress at the moment */ + BUG_ON(!list_empty(&drv->netdev_list)); + + /* + * Try to grab drv->mtx. If a command is still in progress, + * hopefully the driver will refuse it since it's tearing + * down the device already. We wait for this command to complete + * before unlinking the item from the list. + * Note: as codified by the BUG_ON above we cannot get here if + * a virtual interface is still associated. Hence, we can only + * get to lock contention here if userspace issues a command + * that identified the hardware by wiphy index. + */ mutex_lock(&drv->mtx); - list_del(&drv->list); + /* unlock again before freeing */ mutex_unlock(&drv->mtx); + list_del(&drv->list); device_del(&drv->wiphy.dev); debugfs_remove(drv->wiphy.debugfsdir); |
