mac80211: try to workaround some brcmfmac bug with handling interfaces

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Backport of r46278

SVN-Revision: 46289

diff --git a/package/kernel/mac80211/patches/862-brcmfmac-workaround-bug-with-some-inconsistent-BSSes.patch b/package/kernel/mac80211/patches/862-brcmfmac-workaround-bug-with-some-inconsistent-BSSes.patch
new file mode 100644 (file)
index 0000000..542e88b
--- /dev/null
+++ b/package/kernel/mac80211/patches/862-brcmfmac-workaround-bug-with-some-inconsistent-BSSes.patch
@@ -0,0 +1,49 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
+Date: Thu, 9 Jul 2015 00:07:59 +0200
+Subject: [PATCH] brcmfmac: workaround bug with some inconsistent BSSes state
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
+---
+
+--- a/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c
++++ b/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c
+@@ -661,8 +661,36 @@ static struct wireless_dev *brcmf_cfg80211_add_iface(struct wiphy *wiphy,
+                                                    u32 *flags,
+                                                    struct vif_params *params)
+ {
++      struct net_device *dev;
+       struct wireless_dev *wdev;
+ 
++      /*
++       * There is a bug with in-firmware BSS management. When adding virtual
++       * interface brcmfmac first tells firmware to create new BSS and then
++       * it creates new struct net_device.
++       *
++       * If creating/registering netdev(ice) fails, BSS remains in some bugged
++       * state. It conflicts with existing BSSes by overtaking their auth
++       * requests.
++       *
++       * It results in one BSS (addresss X) sending beacons and another BSS
++       * (address Y) replying to authentication requests. This makes interface
++       * unusable as AP.
++       *
++       * To workaround this bug we may try to guess if register_netdev(ice)
++       * will fail. The most obvious case is using interface name that already
++       * exists. This is actually quite likely with brcmfmac & some user space
++       * scripts as brcmfmac doesn't allow deleting virtual interfaces.
++       * So this bug can be triggered even by something trivial like:
++       * iw dev wlan0 delete
++       * iw phy phy0 interface add wlan0 type __ap
++       */
++      dev = dev_get_by_name(&init_net, name);
++      if (dev) {
++              dev_put(dev);
++              return ERR_PTR(-EEXIST);
++      }
++
+       brcmf_dbg(TRACE, "enter: %s type %d\n", name, type);
+       switch (type) {
+       case NL80211_IFTYPE_ADHOC: