package/kernel/mac80211/patches/brcm/861-brcmfmac-workaround-bug-with-some-inconsistent-BSSes.patch

   1 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
   2 Date: Thu, 9 Jul 2015 00:07:59 +0200
   3 Subject: [PATCH] brcmfmac: workaround bug with some inconsistent BSSes state
   4 MIME-Version: 1.0
   5 Content-Type: text/plain; charset=UTF-8
   6 Content-Transfer-Encoding: 8bit
   7
   8 Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
   9 ---
  10
  11 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
  12 +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
  13 @@ -628,8 +628,36 @@ static struct wireless_dev *brcmf_cfg802
  14         struct brcmf_cfg80211_info *cfg = wiphy_to_cfg(wiphy);
  15         struct brcmf_pub *drvr = cfg->pub;
  16         struct wireless_dev *wdev;
  17 +       struct net_device *dev;
  18         int err;
  19
  20 +       /*
  21 +        * There is a bug with in-firmware BSS management. When adding virtual
  22 +        * interface brcmfmac first tells firmware to create new BSS and then
  23 +        * it creates new struct net_device.
  24 +        *
  25 +        * If creating/registering netdev(ice) fails, BSS remains in some bugged
  26 +        * state. It conflicts with existing BSSes by overtaking their auth
  27 +        * requests.
  28 +        *
  29 +        * It results in one BSS (addresss X) sending beacons and another BSS
  30 +        * (address Y) replying to authentication requests. This makes interface
  31 +        * unusable as AP.
  32 +        *
  33 +        * To workaround this bug we may try to guess if register_netdev(ice)
  34 +        * will fail. The most obvious case is using interface name that already
  35 +        * exists. This is actually quite likely with brcmfmac & some user space
  36 +        * scripts as brcmfmac doesn't allow deleting virtual interfaces.
  37 +        * So this bug can be triggered even by something trivial like:
  38 +        * iw dev wlan0 delete
  39 +        * iw phy phy0 interface add wlan0 type __ap
  40 +        */
  41 +       dev = dev_get_by_name(&init_net, name);
  42 +       if (dev) {
  43 +               dev_put(dev);
  44 +               return ERR_PTR(-ENFILE);
  45 +       }
  46 +
  47         brcmf_dbg(TRACE, "enter: %s type %d\n", name, type);
  48         err = brcmf_vif_add_validate(wiphy_to_cfg(wiphy), type);
  49         if (err) {