package/kernel/mac80211/patches/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 @@ -614,9 +614,37 @@ static struct wireless_dev *brcmf_cfg802
  14                                                      enum nl80211_iftype type,
  15                                                      struct vif_params *params)
  16  {
  17 +       struct net_device *dev;
  18         struct wireless_dev *wdev;
  19         int err;
  20
  21 +       /*
  22 +        * There is a bug with in-firmware BSS management. When adding virtual
  23 +        * interface brcmfmac first tells firmware to create new BSS and then
  24 +        * it creates new struct net_device.
  25 +        *
  26 +        * If creating/registering netdev(ice) fails, BSS remains in some bugged
  27 +        * state. It conflicts with existing BSSes by overtaking their auth
  28 +        * requests.
  29 +        *
  30 +        * It results in one BSS (addresss X) sending beacons and another BSS
  31 +        * (address Y) replying to authentication requests. This makes interface
  32 +        * unusable as AP.
  33 +        *
  34 +        * To workaround this bug we may try to guess if register_netdev(ice)
  35 +        * will fail. The most obvious case is using interface name that already
  36 +        * exists. This is actually quite likely with brcmfmac & some user space
  37 +        * scripts as brcmfmac doesn't allow deleting virtual interfaces.
  38 +        * So this bug can be triggered even by something trivial like:
  39 +        * iw dev wlan0 delete
  40 +        * iw phy phy0 interface add wlan0 type __ap
  41 +        */
  42 +       dev = dev_get_by_name(&init_net, name);
  43 +       if (dev) {
  44 +               dev_put(dev);
  45 +               return ERR_PTR(-ENFILE);
  46 +       }
  47 +
  48         brcmf_dbg(TRACE, "enter: %s type %d\n", name, type);
  49         err = brcmf_vif_add_validate(wiphy_to_cfg(wiphy), type);
  50         if (err) {