package/kernel/mac80211/patches/319-0005-brcmfmac-delete-interface-directly-in-code-that-sent.patch

   1 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
   2 Date: Wed, 29 Jun 2016 21:54:26 +0200
   3 Subject: [PATCH] brcmfmac: delete interface directly in code that sent fw
   4  request
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 So far when receiving event about in-firmware-interface removal our
  10 event worker was notifying listener and afterwards it was removing Linux
  11 interface.
  12
  13 First of all it was resulting in slightly unexpected order. The listener
  14 (del_virtual_intf callback) was (usually) returning with success before
  15 we even called unregister_netdev(ice).
  16
  17 Please note this couldn't be simply fixed by changing order of calls in
  18 brcmf_fweh_handle_if_event as unregistering interface earlier could free
  19 struct brcmf_if.
  20
  21 Another problem of current implementation are possible lockups. Focus on
  22 the time slot between calling event handler and removing Linux
  23 interface. During that time original caller may leave (unlocking rtnl
  24 semaphore) *and* another call to the same code may be done (locking it
  25 again). If that happens our event handler will stuck at removing Linux
  26 interface, it won't handle another event and will block process holding
  27 rtnl lock.
  28
  29 This can be simply solved by unregistering interface in a proper
  30 callback, right after receiving confirmation event from firmware. This
  31 only required modifying worker to don't unregister on its own if there
  32 is someone waiting for the event.
  33
  34 Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
  35 Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
  36 ---
  37
  38 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
  39 +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
  40 @@ -18,6 +18,7 @@
  41  #include "brcmu_wifi.h"
  42  #include "brcmu_utils.h"
  43
  44 +#include "cfg80211.h"
  45  #include "core.h"
  46  #include "debug.h"
  47  #include "tracepoint.h"
  48 @@ -182,8 +183,13 @@ static void brcmf_fweh_handle_if_event(s
  49
  50         err = brcmf_fweh_call_event_handler(ifp, emsg->event_code, emsg, data);
  51
  52 -       if (ifp && ifevent->action == BRCMF_E_IF_DEL)
  53 -               brcmf_remove_interface(ifp, false);
  54 +       if (ifp && ifevent->action == BRCMF_E_IF_DEL) {
  55 +               bool armed = brcmf_cfg80211_vif_event_armed(drvr->config);
  56 +
  57 +               /* Default handling in case no-one waits for this event */
  58 +               if (!armed)
  59 +                       brcmf_remove_interface(ifp, false);
  60 +       }
  61  }
  62
  63  /**
  64 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
  65 +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
  66 @@ -2290,8 +2290,7 @@ int brcmf_p2p_del_vif(struct wiphy *wiph
  67                 else
  68                         err = 0;
  69         }
  70 -       if (err)
  71 -               brcmf_remove_interface(vif->ifp, true);
  72 +       brcmf_remove_interface(vif->ifp, true);
  73
  74         brcmf_cfg80211_arm_vif_event(cfg, NULL);
  75         if (vif->wdev.iftype != NL80211_IFTYPE_P2P_DEVICE)